CN110048445B - Elevator energy-saving device - Google Patents
Elevator energy-saving device Download PDFInfo
- Publication number
- CN110048445B CN110048445B CN201810043104.9A CN201810043104A CN110048445B CN 110048445 B CN110048445 B CN 110048445B CN 201810043104 A CN201810043104 A CN 201810043104A CN 110048445 B CN110048445 B CN 110048445B
- Authority
- CN
- China
- Prior art keywords
- direct current
- bus
- current bus
- energy
- electric energy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
- H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Elevator Control (AREA)
Abstract
The invention discloses an energy-saving device for an elevator, wherein two direct current input ends of each inverter are respectively connected with a direct current bus, and alternating current output ends of the inverters are respectively connected with different motors; the output power of the inverter is positive in the electric state, and the output power of the inverter is negative in the regeneration state; the main power supply of the electrical equipment is a DC/DC unidirectional converter and/or a unidirectional converter DC/AC unidirectional converter; the main power supply of the electrical equipment provides the electric energy of the direct current bus to the electrical equipment; when the sum of the output power of each inversion device and each electrical equipment total power supply which are connected in parallel on the direct current bus is negative and the voltage of the direct current bus is higher, the electric energy on the direct current bus is transmitted to the energy storage device; when the sum of the output power of the inverter devices and the total power supply of the electrical equipment which are connected in parallel on the direct current bus is positive and the voltage of the direct current bus is lower, the electric energy on the energy storage device is transmitted to the direct current bus. The invention has the advantages of high energy-saving efficiency, low pressure on the energy storage device and low cost.
Description
Technical Field
The invention relates to an elevator control technology, in particular to an elevator energy-saving device.
Background
With the energy conservation and environmental protection in the heart, a plurality of energy-saving devices appear in the field of elevators, so that the energy-saving efficiency is improved, the requirements of the energy-saving devices are reduced, and the energy-saving device is a target pursued by various manufacturers.
These energy saving devices typically include an energy storage device with an energy management device. In order to increase the frequency of use of the energy storage device and thus the overall energy saving efficiency of the elevator, manufacturers have proposed that the direct current buses connected to a plurality of elevator inverter devices are connected in parallel.
After the direct current buses are connected in parallel, when the inverter device performs regeneration operation simultaneously, the power fed back to the direct current buses is larger, so that higher requirements are provided for devices such as a reactor, an insulated gate bipolar transistor, a freewheeling diode and a super capacitor in the energy storage device. Each manufacturer may balance the advantages and disadvantages between the cost increase caused by improving the specification of the device and the improvement of the overall energy-saving efficiency caused by connecting the inverter with the direct current bus in parallel, and selects a proper intermediate point for design.
Disclosure of Invention
The invention aims to provide an elevator energy-saving device which is high in energy-saving efficiency, reduces the pressure on energy storage devices and does not increase the overall cost additionally.
In order to solve the technical problem, the invention provides an elevator energy-saving device which comprises a direct current bus, an energy storage device, a power detection device, at least one inverter and at least one electrical equipment main power supply, wherein the direct current bus is connected with the energy storage device;
two direct current input ends of each inverter are respectively connected with a positive bus and a negative bus of the direct current bus, and an alternating current output end of each inverter is respectively connected with different motors;
the inverter has two states, namely an electric state and a regeneration state, the output power of the inverter is positive in the electric state, and the electric energy of the direct-current bus is provided for the motor; when the power is in a regeneration state, the output power of the inverter is negative, and the motor feedback electric energy is transmitted to the direct current bus;
the main power supply of the electrical equipment is a DC/DC unidirectional converter and/or a unidirectional converter DC/AC unidirectional converter;
two direct current input ends of the main power supply of each electrical device are respectively connected with a positive bus and a negative bus of the direct current bus, and the output is connected with the electrical device; the output power of the total power supply of the electrical equipment is more than or equal to 0, and the electric energy of the direct current bus is provided for the electrical equipment;
the power detection device is used for detecting the sum of the output power of each inversion device connected to the bus and the total power supply of the electrical equipment;
the energy storage device is connected between the positive bus and the negative bus;
the energy storage device comprises an electric energy management device and a super capacitor;
the electric energy management device is used for allocating the electric energy flow direction between the direct current bus and the super capacitor;
when the sum of the output power of each inversion device and each electrical equipment total power supply which are connected in parallel on the direct current bus is negative, and the voltage of the direct current bus is higher than a first set voltage X, the electric energy management device controls the electric energy on the direct current bus to be transmitted to the super capacitor;
when the sum of the output power of each inverter and each electrical equipment main power supply which are connected in parallel on the direct current bus is positive, and the voltage of the direct current bus is lower than a second set voltage Y, the electric energy management device controls the electric energy on the super capacitor to be transmitted to the direct current bus;
the first setting voltage X is greater than the second setting voltage Y.
Preferably, the elevator energy-saving device also comprises a rectifier bridge pile;
the rectifier bridge stack converts alternating current commercial power into direct current and provides the direct current to the direct current bus;
the output voltage of the rectifier bridge stack is greater than the second set voltage Y and less than the first set voltage X.
Preferably, the elevator energy-saving device also comprises a regenerative energy consumption device;
the regenerative energy consumption device comprises a regenerative resistor and a brake switch which are connected in series between a positive bus and a negative bus.
Preferably, the power management device includes a first insulated gate bipolar transistor, a second insulated gate bipolar transistor, a first inductor, a third diode, and a fourth diode;
the emitter of the first insulated gate bipolar transistor is connected with the collector of the second insulated gate bipolar transistor;
the collector of the first insulated gate bipolar transistor and the emitter of the second insulated gate bipolar transistor are respectively connected with the positive bus and the negative bus;
the first inductor is connected with the emitter of the first insulated gate bipolar transistor in a terminating mode, and the other end of the first inductor is connected with the anode of the super capacitor in a terminating mode;
the negative electrode of the super capacitor is connected with a negative bus;
the negative end of the third diode is connected with the positive bus, and the positive end of the third diode is connected with the positive electrode of the super capacitor;
the negative end of the fourth diode is connected with the positive electrode of the super capacitor, and the positive end of the fourth diode is connected with the negative bus.
Preferably, the capacity of the super capacitor is 250 Wh.
Preferably, the output voltage of the rectifier bridge stack is 540V;
the first setting voltage X is 630V;
the second setting voltage Y is 530V.
According to the elevator energy-saving device, when the total output power of the inverter devices connected in parallel on the direct-current bus is negative, the regenerated electric energy of the motor is transmitted to the main power supply of the electrical equipment from the inverter devices through the direct-current bus, and compared with the energy-saving path which is not provided with the main power supply of the electrical equipment, the regenerated electric energy is transmitted to the energy storage device from the inverter devices through the direct-current bus, and then is transmitted to the path of the direct-current bus from the energy storage device when in use, the energy-saving device has few conversion links, so that the energy-saving. Because the main power supply of the electrical equipment consumes the electric energy all the time when the elevator is electrified, the requirement of the electric energy power which needs to be fed back to the energy storage device can be properly reduced, the pressure on devices of the energy storage device is reduced, the requirement of the resistance power consumption of the regenerative energy consumption device can be reduced, and the increase of the whole cost is not additionally brought.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the present invention are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural view of an embodiment of an elevator energy-saving device of the invention;
fig. 2 is a circuit diagram of an energy storage device of an embodiment of the elevator energy saving device of the present invention.
Description of reference numerals:
1: a rectifier bridge stack; 2: a direct current bus; 3: an inverter device; 4: an energy storage device; 41: an electric energy management device; 42: a super capacitor; 5: a main power supply for the electrical equipment; 6: regenerative energy consumption device
Detailed Description
The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
As shown in fig. 1, the elevator energy-saving device comprises a direct current bus 2, an energy storage device 4, a power detection device, at least one inverter device 3 and at least one electrical equipment main power supply 5;
two direct current input ends of each inverter 3 are respectively connected with a positive bus and a negative bus of the direct current bus 2, and an alternating current output end is respectively connected with different motors M;
the inverter device 3 has two states of an electric state and a regeneration state, the output power of the inverter device is positive in the electric state, and the direct current bus electric energy is provided to the motor; when the power is in a regeneration state, the output power of the inverter is negative, and the motor feedback electric energy is transmitted to the direct current bus;
two direct current input ends of the main power supply of each electrical device are respectively connected with a positive bus and a negative bus of the direct current bus, and the output is connected with the electrical device; the output power of the total power supply of the electrical equipment is more than or equal to 0, and the electric energy of the direct current bus is provided for the electrical equipment;
the power detection device is used for detecting the sum of the output power of each inversion device connected to the bus and the total power supply of the electrical equipment;
the main power supply of the electrical equipment is a DC/DC unidirectional converter and/or a unidirectional converter DC/AC unidirectional converter; the main power supply of the electrical equipment converts the electric energy of the direct current bus into direct current or alternating current with different voltage grades to be supplied to the electrical equipment of the elevator, and the electrical equipment is generally a DC/DC one-way converter and can also be a DC/AC one-way converter;
the energy storage device is connected between the positive bus and the negative bus;
the energy storage device comprises an electric energy management device 41 and a super capacitor 42;
the electric energy management device 41 is used for allocating the electric energy flow direction between the direct current bus 2 and the super capacitor 42, and the super capacitor can store electric energy with a certain capacity;
when the sum of the output power of each inversion device and each electrical equipment total power supply which are connected in parallel on the direct current bus is negative, and the voltage of the direct current bus is higher than a first set voltage X, the electric energy management device controls the electric energy on the direct current bus to be transmitted to the super capacitor;
when the sum of the output power of each inverter and each electrical equipment main power supply which are connected in parallel on the direct current bus is positive, and the voltage of the direct current bus is lower than a second set voltage Y, the electric energy management device controls the electric energy on the super capacitor to be transmitted to the direct current bus;
the first setting voltage X is greater than the second setting voltage Y.
Preferably, the elevator energy-saving device also comprises a rectifier bridge stack 1;
the rectifier bridge stack 1 converts alternating current commercial power into direct current and provides the direct current to the direct current bus 2;
the output voltage of the rectifier bridge stack 1 is greater than the second set voltage Y and less than the first set voltage X.
Preferably, the elevator energy-saving device also comprises a regenerative energy consumption device;
the regenerative energy consumption device 6 comprises a regenerative resistor and a brake switch which are connected in series between a positive bus and a negative bus.
According to the elevator energy-saving device, the main power supply of the electrical equipment provides all electric energy required by normal operation and operation under all special working conditions of the elevator, and the main power supply of the electrical equipment acquires the electric energy from the direct-current bus no matter which operation state the inverter devices connected in parallel on the direct-current bus are in. When the total output power of the inverter devices connected in parallel on the direct current bus is negative, the voltage of the bus is increased (higher than the output voltage of the rectifier bridge stack), and the electric energy of the direct current bus is mainly provided by the inverter devices; when the total output power of the inverter devices connected in parallel on the direct current bus is positive, the electric energy of the direct current bus is provided by an external power supply and/or an energy storage device. When the total output power of the inverter devices connected in parallel on the direct current bus is negative, the regenerated electric energy of the motor is transmitted to the main power supply of the electrical equipment from the inverter devices through the direct current bus, compared with the energy-saving path which is not configured with the main power supply of the electrical equipment, the regenerated electric energy is transmitted to the energy storage device from the inverter devices through the direct current bus, and is transmitted to the path of the direct current bus from the energy storage device when in use, the energy-saving path has fewer conversion links, so that the energy-saving efficiency is high (the energy-saving efficiency refers to the ratio of the electric energy saved when the energy-saving device is configured to the electric energy consumed when. Because the main power supply of the electrical equipment consumes the electric energy all the time when the elevator is electrified, the requirement of the electric energy power which needs to be fed back to the energy storage device can be properly reduced, the pressure on devices of the energy storage device is reduced, the requirement of the resistance power consumption of the regenerative energy consumption device can be reduced, and the increase of the whole cost is not additionally brought.
Example two
As shown in fig. 2, the power management device of the elevator according to the first embodiment includes a first insulated gate bipolar transistor IGBT1, a second insulated gate bipolar transistor IGBT2, a first inductor L1, a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4;
the emitter of the first insulated gate bipolar transistor is connected with the collector of the second insulated gate bipolar transistor;
the collector of the first insulated gate bipolar transistor and the emitter of the second insulated gate bipolar transistor are respectively connected with the positive bus and the negative bus;
the first inductor is connected with the emitter of the first insulated gate bipolar transistor in a terminating mode, and the other end of the first inductor is connected with the anode of the super capacitor in a terminating mode;
the negative electrode of the super capacitor is connected with a negative bus;
the negative end of the third diode is connected with the positive bus, and the positive end of the third diode is connected with the positive electrode of the super capacitor;
the negative end of the fourth diode is connected with the positive electrode of the super capacitor, and the positive end of the fourth diode is connected with the negative bus.
Two ends of the first diode D1 are respectively connected with an emitter and a collector of the first insulated gate bipolar transistor IGBT 1;
both ends of the second diode D2 are connected to the emitter and the collector of the second insulated-gate bipolar transistor IGBT2, respectively.
In the energy saving device for an elevator of the second embodiment, the rated current specifications of the reactor, the insulated gate bipolar transistor, the freewheeling diode, the super capacitor and other devices in the energy storage device can be correspondingly reduced,
EXAMPLE III
Based on the first embodiment, the elevator energy-saving device has three elevator group controls, and the specifications of the three elevators are that the rated load is 1050kg, the rated speed is 1.75m/s, and the capacity of the energy storage device is 250 Wh. The inverter of the three elevators is connected in parallel with the direct current bus, and the main power supply of the electrical equipment of the three elevators is also connected in parallel with the direct current bus.
The average regenerative power of 6KW is generated during the regenerative operation of the elevator with the specification, the average power of the electrical equipment main power supply of the elevator during the normal operation is 600W, the average power of the electrical equipment main power supply in the standby state is 100W, the voltage of a direct-current bus is 540V, the direct-current bus is set to be larger than 630V, a starting energy storage device absorbs the electric energy of the direct-current bus, and the direct-current bus is set to be smaller than 530V, and the starting energy storage device releases the electric energy to the direct-current. The super capacitor voltage range of the energy storage device is 100V to 200V.
Supposing that one elevator inverter is in a regeneration state at a certain moment, the other two elevators stop, the total output power of the inverter connected in parallel on the direct current bus is-6 KW, the total power of all electrical equipment connected in parallel is 1.8KW, the sum of the two is-4.2 KW, the feedback current range is 30-60A considering the common elevator energy-saving device, and the feedback current range is 21-42A considering the utilization of the characteristics of the invention, and the requirement of the feedback power is greatly reduced.
When the voltage of the bus is about 540V at the beginning, the voltage of the direct current bus is gradually increased because the electric energy of the inverter is continuously fed back to the direct current bus, and after the voltage of the direct current bus reaches 630V, the energy storage device is started to absorb the electric energy of the direct current bus, and the voltage of the super capacitor is gradually increased.
When the elevator in the regeneration state is in the standby state after being stopped, the total power of the inverter devices connected in parallel on the direct current bus is 0KW, the total power of all electrical equipment connected in parallel is 300W, and the sum of the total power of all the electrical equipment connected in parallel and the total power of all the electrical equipment connected in parallel is 300W.
The above are merely preferred embodiments of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (6)
1. An elevator energy-saving device is characterized by comprising a direct current bus, an energy storage device, a power detection device, at least two inverter devices and at least one electrical equipment main power supply;
two direct current input ends of each inverter are respectively connected with a positive bus and a negative bus of the direct current bus, and an alternating current output end of each inverter is respectively connected with different motors;
the inverter has two states, namely an electric state and a regeneration state, the output power of the inverter is positive in the electric state, and the electric energy of the direct-current bus is provided for the motor; when the power is in a regeneration state, the output power of the inverter is negative, and the motor feedback electric energy is transmitted to the direct current bus;
the main power supply of the electrical equipment is a DC/DC unidirectional converter and/or a unidirectional converter DC/AC unidirectional converter;
two direct current input ends of the main power supply of each electrical device are respectively connected with a positive bus and a negative bus of the direct current bus, and the output is connected with the electrical device; the output power of the total power supply of the electrical equipment is more than or equal to 0, and the electric energy of the direct current bus is provided for the electrical equipment;
the power detection device is used for detecting the sum of the output power of each inversion device connected to the bus and the total power supply of the electrical equipment;
the energy storage device is connected between the positive bus and the negative bus;
the energy storage device comprises an electric energy management device and a super capacitor;
the electric energy management device is used for allocating the electric energy flow direction between the direct current bus and the super capacitor;
when the sum of the output power of each inversion device and each electrical equipment total power supply which are connected in parallel on the direct current bus is negative, and the voltage of the direct current bus is higher than a first set voltage X, the electric energy management device controls the electric energy on the direct current bus to be transmitted to the super capacitor;
when the sum of the output power of each inverter and each electrical equipment main power supply which are connected in parallel on the direct current bus is positive, and the voltage of the direct current bus is lower than a second set voltage Y, the electric energy management device controls the electric energy on the super capacitor to be transmitted to the direct current bus;
the first setting voltage X is greater than the second setting voltage Y.
2. The elevator energy saving device according to claim 1,
the elevator energy-saving device also comprises a rectifier bridge pile;
the rectifier bridge stack converts alternating current commercial power into direct current and provides the direct current to the direct current bus;
the output voltage of the rectifier bridge stack is greater than the second set voltage Y and less than the first set voltage X.
3. The elevator energy saving device according to claim 1,
the elevator energy-saving device also comprises a regenerative energy consumption device;
the regenerative energy consumption device comprises a regenerative resistor and a brake switch which are connected in series between a positive bus and a negative bus.
4. The elevator energy saving device according to claim 1,
the electric energy management device comprises a first insulated gate bipolar transistor, a second insulated gate bipolar transistor, a first inductor, a third diode and a fourth diode;
the emitter of the first insulated gate bipolar transistor is connected with the collector of the second insulated gate bipolar transistor;
the collector of the first insulated gate bipolar transistor and the emitter of the second insulated gate bipolar transistor are respectively connected with the positive bus and the negative bus;
the first inductor is connected with the emitter of the first insulated gate bipolar transistor in a terminating mode, and the other end of the first inductor is connected with the anode of the super capacitor in a terminating mode;
the negative electrode of the super capacitor is connected with a negative bus;
the negative end of the third diode is connected with the positive bus, and the positive end of the third diode is connected with the positive electrode of the super capacitor;
the negative end of the fourth diode is connected with the positive electrode of the super capacitor, and the positive end of the fourth diode is connected with the negative bus.
5. The elevator energy saving device according to claim 1,
the capacity of the super capacitor is 250 Wh.
6. The elevator energy saving device according to claim 2,
the output voltage of the rectifier bridge stack is 540V;
the first setting voltage X is 630V;
the second setting voltage Y is 530V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810043104.9A CN110048445B (en) | 2018-01-17 | 2018-01-17 | Elevator energy-saving device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810043104.9A CN110048445B (en) | 2018-01-17 | 2018-01-17 | Elevator energy-saving device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110048445A CN110048445A (en) | 2019-07-23 |
| CN110048445B true CN110048445B (en) | 2021-05-25 |
Family
ID=67273029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810043104.9A Active CN110048445B (en) | 2018-01-17 | 2018-01-17 | Elevator energy-saving device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110048445B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5712456A (en) * | 1996-04-10 | 1998-01-27 | Otis Elevator Company | Flywheel energy storage for operating elevators |
| CN102180390A (en) * | 2011-03-08 | 2011-09-14 | 苏州圣元电器有限公司 | Frequency-conversion traction equipment energy-saving system for elevator |
| CN102372198A (en) * | 2010-08-12 | 2012-03-14 | 上海三菱电梯有限公司 | Control device for elevator |
| CN103001238A (en) * | 2011-09-19 | 2013-03-27 | 上海三菱电梯有限公司 | Elevator energy saving system |
| CN106385095A (en) * | 2016-08-30 | 2017-02-08 | 成都英格瑞德电气有限公司 | Module applicable to energy storage power generation scheme of elevator |
-
2018
- 2018-01-17 CN CN201810043104.9A patent/CN110048445B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5712456A (en) * | 1996-04-10 | 1998-01-27 | Otis Elevator Company | Flywheel energy storage for operating elevators |
| CN102372198A (en) * | 2010-08-12 | 2012-03-14 | 上海三菱电梯有限公司 | Control device for elevator |
| CN102180390A (en) * | 2011-03-08 | 2011-09-14 | 苏州圣元电器有限公司 | Frequency-conversion traction equipment energy-saving system for elevator |
| CN103001238A (en) * | 2011-09-19 | 2013-03-27 | 上海三菱电梯有限公司 | Elevator energy saving system |
| CN106385095A (en) * | 2016-08-30 | 2017-02-08 | 成都英格瑞德电气有限公司 | Module applicable to energy storage power generation scheme of elevator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110048445A (en) | 2019-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101374982B1 (en) | Power converter | |
| Grbovic et al. | The ultracapacitor-based regenerative controlled electric drives with power-smoothing capability | |
| Grbović et al. | The ultracapacitor-based controlled electric drives with braking and ride-through capability: Overview and analysis | |
| CN102211724B (en) | Novel energy-saving elevator using super capacitor | |
| Grbovic et al. | A three-terminal ultracapacitor-based energy storage and PFC device for regenerative controlled electric drives | |
| US7605497B2 (en) | Two-source inverter | |
| JP2009027815A (en) | Grid-connected converter device | |
| CN113224808A (en) | Novel elevator energy-saving device based on super capacitor | |
| JP2011522511A (en) | Energy recovery device for variable speed drive | |
| CN101950978A (en) | Energy-saving emergency type elevator feedback power system | |
| CN110048445B (en) | Elevator energy-saving device | |
| CN109455605B (en) | Elevator energy-saving device | |
| CN102223136A (en) | Non-energy-storing motor-driven system for complementary power supply of wind power generation and electrical network | |
| US20230253877A1 (en) | Power factor correction and dc-dc multiplexing converter and uninterruptible power supply including the same | |
| CN201201829Y (en) | Energy resource feedback system for elevator | |
| CN113922669B (en) | Conversion circuit, conversion device and power taking power generation system | |
| CN111052582B (en) | Frequency converter, frequency converter assembly and control method of frequency converter assembly | |
| CN203411208U (en) | Energy-storage type lifter | |
| CN201504218U (en) | Power-saving frequency converter for elevators | |
| US11444547B2 (en) | Power conversion apparatus | |
| CN114362311A (en) | Power supply system of direct-current bidirectional energy storage elevator | |
| CN109516326B (en) | Multi-elevator control system | |
| CN201282431Y (en) | Active feedback device | |
| CN109617042A (en) | A kind of control device of industrial sewing machine DC bus-bar voltage | |
| CN111071875A (en) | Decentralized power management in an elevator system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |