CN201113403Y - Elevator high-power electronic energy-saving device - Google Patents

Abstract

A multi-disciplinary technical field involving electronics, information, and energy, especially a high-power electronic energy-saving device for elevators, which is a high-tech elevator energy-saving device that uses modern scientific and technological means. The device is composed of filters, frequency converters, motors and logic circuits, and at least includes: logic protection modules, single-chip controllers, elevator regenerative DC power supplies, insulated gate bipolar transistor IGBT inverter bridges, AC grids and synchronous detection modules An electronic energy-saving device combined into an inverter synchronous circuit; it mainly solves related technical problems such as how to feed back the output energy of the motor to the power grid when the motor is generating power during the operation of the variable-frequency speed-regulating elevator. The positive effects of the utility model are: utilizing modern power electronic technology, control technology and computer technology, realizing the feedback of the regenerative energy of the elevator system to the AC power grid, and carrying out the protection of system overvoltage, overcurrent and overheating safety, with simple and effective control Etc.

Description

Elevator high-power electronic energy-saving device

technical field

The utility model relates to a multidisciplinary technical field of electronics, information and energy, in particular to a high-power electronic energy-saving device for elevators, which is a high-tech technical product mainly used to realize energy-saving of elevators by using modern scientific and technological means.

Background technique

At present, almost all AC-DC-AC inverters are used as speed control tools for driving motors in elevator operation control systems. This type of inverter has high power factor, high efficiency, high precision and wide speed range, so it is widely used. Frequency conversion speed regulation technology involves many disciplines such as electronics, electrical engineering, information and control. Adopting frequency conversion speed regulation technology is an important way to save energy, reduce consumption, improve control performance, and improve product quality. It has achieved good application results and significant economic benefits in application. However, in terms of elevator operation and control, there are still problems of further excavating the energy-saving potential of the frequency conversion speed regulation system and improving efficiency. There are two important ways to solve this problem. One is to adopt a control strategy to minimize the loss and maximize the efficiency of the variable frequency drive motor; the other is to use a technical means to make the energy stored in the production machinery fed back to the grid in a timely and efficient manner. The first problem can be achieved through frequency conversion speed regulation technology and its optimal control technology to achieve "on-demand energy supply", that is, to minimize the input energy of the frequency conversion device under the premise of meeting the production machinery speed, torque and dynamic response requirements; the second This problem can feed back the regenerative energy stored on the DC side of the inverter to the AC grid through the active inverter device. This patent relates to the second problem of energy-saving control of frequency-variable speed-regulating elevators—the energy feedback control technology of AC-DC-AC frequency-variable speed-regulating elevators.

The problems existing in the application of variable frequency elevators are:

Most general-purpose inverters are voltage-type AC-DC-AC inverters. The principle of this type of frequency converter is that the three-phase alternating current first passes through the diode uncontrolled rectifier bridge to obtain pulsating direct current, then filters and stabilizes the voltage through electrolytic capacitors, and finally supplies power to the motor through active inverter output voltage and adjustable frequency alternating current. However, general-purpose frequency converters cannot be directly used in speed-regulating systems that require fast starting and braking and frequent forward and reverse rotation, and cannot feed back the electric energy generated by the motor to the power grid. Because this system requires the motor to run in four quadrants, when the elevator decelerates, brakes and the elevator goes up, the motor is in the state of regenerative power generation. Since the diode of the frequency converter does not control the energy transmission of the rectifier and is irreversible, the generated regenerative power is transmitted to the filter capacitor on the DC side to generate a pumped voltage. Excessive pumping voltage may damage switching devices, electrolytic capacitors, and even damage the insulation of the motor, thus threatening the safe operation of the system. At present, this part of energy can only be consumed in the form of heat energy through energy-consuming resistors. Due to serious heating of resistors , so that the reliability and stability of the system are adversely affected.

Research status of elevator energy feedback technology at home and abroad:

In order to solve the regenerative energy generated by the elevator in the state of regenerative power generation, Germany's Siemens has launched a voltage-type AC-DC-AC inverter for four-quadrant operation of the motor, and Japan, Canada and other countries have also successfully developed power regeneration devices. At the same time, it has been seen that there are reports on the development of four-quadrant voltage AC-DC-AC converters and grid-side pulse rectifiers abroad. The common problem is that these devices are expensive, and some products have high requirements on the power grid, which is not suitable for my country's national conditions. Most domestic small and medium-capacity systems adopt energy-consuming braking, that is, the electric energy is consumed in high-power resistors to realize the four-quadrant operation of the motor through built-in or external braking resistors. Although this method is simple, it has the following serious disadvantages :

(1) Waste energy and reduce system efficiency. (2) The resistance heats up seriously, which affects the normal operation of other parts of the system. (3) Simple energy-consuming braking sometimes cannot suppress the pumping voltage generated by rapid braking in time, which limits the improvement of braking performance.

There have been reports of energy-saving systems for hydraulic elevators in China, but there are relatively few studies on energy-saving elevators using energy feedback control technology. The research on energy-saving aspects of elevator energy feedback electronics has not yet seen the report of practical products.

Contents of the invention

In order to overcome the above shortcomings, the main purpose of this utility model is to provide a direct control of the grid line voltage as the object. The DC side voltage of the frequency converter is converted as the power supply for the control circuit. There are three power inverter controllers used. The bridge arm is composed of six IGBTs (Insulated Gate Bipolar Transistor, Insulated Gate Bipolar Transistor), and a 89C52 single-chip microcomputer is used to generate inverter control signals and perform system overvoltage, overcurrent, and overheat safety protection, and can regenerate electric energy of the elevator An elevator high-power electronic energy-saving device that feeds back to the AC grid.

The technical problem to be solved by the utility model is: mainly solving the technical problem of how to feed back the output energy of the motor under the power generation state of the frequency conversion speed control elevator to the power grid, and how to realize the regeneration energy of the elevator system by using modern power electronic technology, control technology and computer technology Feedback to the AC grid and other related technical issues.

The technical solution adopted by the utility model to solve its technical problems is: the device is made up of components such as filter, rectifier, frequency converter, motor, power supply, logic circuit and single-chip microcomputer, and the device at least includes:

An electronic energy-saving device that combines a logic protection module, a single-chip controller, an elevator regenerative DC power supply, an insulated gate bipolar transistor IGBT inverter bridge, an AC power grid, and a synchronous detection module into an inverter synchronous circuit;

The output terminal of a logic protection module is connected with the input terminal of the single-chip controller module, and the output terminal of the single-chip controller module is connected with the input terminal of the insulated gate bipolar transistor IGBT inverter bridge module, and the insulated gate bipolar transistor IGBT One output end of the inverter bridge module is connected to the input end of the logic protection module, and the other output end is connected to the input end of the AC grid module;

The output end of an elevator regenerative DC power supply module is connected with the input end of an insulated gate bipolar transistor IGBT inverter bridge module;

The output end of an AC grid module is connected with the input end of the single-chip controller module after passing through the synchronous detection module.

The computer control of the single-chip controller of the high-power electronic energy-saving device of the elevator and the input signals of the logic protection circuit include a three-phase synchronous signal and an overcurrent and overvoltage protection signal, and the output signal is the conducting and switching of six IGBTs of the inverter controller. shutdown control signal, where:

One of the pin P1.0 of the single-chip controller is connected with the second pin of the NOR gate A, and one of the pin P1.1 of the single-chip controller is connected with the third pin of the NOR gate A through the inverter. connected, the first pin of the NOR gate A is connected to the overcurrent protection terminal;

The other way of the pin P1.1 of the single-chip controller is connected with the second pin of the NOR gate B, and the other way of the pin P1.0 of the single-chip controller is connected with the third lead of the inverter and the NOR gate B. The pin is connected, and the first pin of the NOR gate B is connected to the overcurrent protection terminal;

One of the pins P1.2 of the single-chip controller is connected to the second pin of the NOR gate C, and the other is connected to the third pin of the NOR gate D through the inverter, and the pin P1 of the single-chip controller .3 One path through the inverter is connected to the third pin of the NOR gate C, and the first pin of the NOR gate C is connected to the overcurrent protection terminal;

The other way of the pin P1.3 of the single-chip controller is connected with the second pin of the NOR gate D, and the other way of the pin P1.2 of the single-chip controller is connected with the third lead of the inverter and the NOR gate D. The pin is connected, and the first pin of the NOR gate D is connected with the overcurrent protection terminal;

One of the pins P1.4 of the microcontroller controller is connected to the second pin of the NOR gate E, and the other is connected to the third pin of the NOR gate F through the inverter, and the pin P1 of the microcontroller controller .5 is connected to the third pin of the NOR gate E through the inverter, and the first pin of the NOR gate E is connected to the overcurrent protection terminal;

One of the pins P1.5 of the single-chip controller is connected with the second pin of the NOR gate F, and the other is connected with the third pin of the NOR gate E through the inverter, and the pin P1 of the single-chip controller The other path of .4 is connected to the third pin of the NOR gate F through the inverter, and the first pin of the NOR gate F is connected to the overcurrent protection terminal;

The outputs of the NOR gate A, the NOR gate B, the NOR gate C, the NOR gate D, the NOR gate E and the NOR gate F are respectively connected to the bases of the insulated gate bipolar transistors through inverters , is the control signal output by the computer.

The AB phase-line voltages of the insulated gate bipolar transistor IGBT inverter bridge of the described elevator high-power electronic energy-saving device are respectively connected with the IGBT insulated gate bipolar transistors T1, T2, T3, and T4; T1 and T4 are turned on at the moment of 1 degree phase, T1 and T4 are cut off at 120 degree phase of AB phase line voltage; T2 and T3 are turned on at 240 degree phase of AB phase line voltage, and T2 is turned on at 300 degree phase of AB phase line voltage , T3 deadline;

The BC phase-line voltages of the insulated gate bipolar transistor IGBT inverter bridge are connected to the IGBT insulated gate bipolar transistors T3, T4, T5, and T6 respectively; at the 60-degree phase moment of the BC phase line voltage, T3, T6 is turned on, and T3 and T6 are cut off at 120-degree phase of BC phase-line voltage; T4 and T5 are turned on at 240-degree phase of BC phase-line voltage, and T4 and T5 are cut off at 300-degree phase of BC phase-line voltage;

The CA phase-line voltages of the insulated gate bipolar transistor IGBT inverter bridge are respectively connected to the IGBT insulated gate bipolar transistors T5, T6, T1, and T2; at the 60-degree phase moment of the CA phase line voltage, T5, T2 is turned on, and T5 and T2 are cut off at the 120-degree phase of CA phase-line voltage; T6 and T1 are turned on at 240-degree phase of CA phase-line voltage, and T6 and T1 are cut off at 300-degree phase of CA phase-line voltage.

The single-chip controller of the high-power electronic energy-saving device of the elevator is a 51 series single-chip microprocessor 89C52.

The beneficial effects of the utility model are: the device solves the technical problem that the motor output energy is fed back to the power grid in the state of motor power generation during the operation of the variable-frequency speed-regulating elevator, and utilizes modern power electronics technology, control technology, and computer technology to realize the regeneration of the elevator system. The feedback of the AC power grid, and the protection of the system overvoltage, overcurrent, and overheating safety, have the advantages of simple and effective control.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Accompanying drawing 1 is the circuit block schematic diagram of the overall structure of the utility model;

Accompanying drawing 2 is a schematic diagram of the utility model computer control and logic protection circuit;

Accompanying drawing 3 is the utility model inverter bridge circuit schematic diagram;

Explanation of the numbers in the accompanying drawings:

1-logic protection;

2-Single chip controller;

3- Elevator regenerative DC power supply;

4- Insulated gate bipolar transistor IGBT inverter bridge;

5 - AC grid;

6-synchronous detection;

10-overcurrent protection;

20-NOR gate A;

21-NOR gate B;

22-NOR gate C;

23-NOR gate D;

24-NOR gate E;

25- NOR Gate F

Detailed ways

See accompanying drawing 1,2, shown in 3, the utility model is made up of components such as filter, rectifier, frequency converter, motor, power supply, logic circuit and single-chip microcomputer, and this device comprises at least:

Logic protection 1 module, single-chip controller 2, elevator regenerative DC power supply 3, insulated gate bipolar transistor IGBT inverter bridge 4, AC power grid 5 and synchronous detection 6 modules are combined into an electronic energy-saving device for an inverter synchronous circuit;

The output terminal of a logic protection module 1 is connected to the input terminal of the single-chip controller module 2, and the output terminal of the single-chip controller module 2 is connected to the input terminal of the insulated gate bipolar transistor IGBT inverter bridge 4 module. One output terminal of the polar transistor IGBT inverter bridge 4 module is connected to the input terminal of the logic protection module 1, and the other output terminal is connected to the input terminal of the AC grid 5 module;

The output terminal of the module 3 of the regenerative DC power supply for an elevator is connected to the input terminal of the module 4 of the insulated gate bipolar transistor IGBT inverter bridge;

The output terminal of the AC grid 5 module is connected with the input terminal of the single-chip controller 2 module after passing through the synchronous detection 6 module.

The computer control of the single-chip controller 2 of the high-power electronic energy-saving device of the elevator and the input signals of the logic protection circuit have a three-phase synchronous signal and an overcurrent and overvoltage protection signal, and the output signal is the conduction of six IGBTs of the inverter controller. and shutdown control signals, where:

One of the pins P1.0 of the single-chip controller 2 is connected with the second pin of the NOR gate A20, and one of the pins P1.1 of the single-chip controller 2 is connected to the third pin of the inverter and the NOR gate A20. The pin is connected, and the first pin of the NOR gate A20 is connected with the overcurrent protection terminal 10;

The other way of the pin P1.1 of the single-chip controller 2 is connected with the second pin of the NOR gate B21, and the other way of the pin P1.0 of the single-chip controller 2 is passed through the inverter and the second pin of the NOR gate B21 The three pins are connected, and the first pin of the NOR gate B21 is connected with the overcurrent protection terminal 10;

One of the pins P1.2 of the single-chip controller 2 is connected with the second pin of the NOR gate C22, and the other is connected with the third pin of the NOR gate D23 through the inverter. One path of the pin P1.3 is connected to the third pin of the NOR gate C22 through the inverter, and the first pin of the NOR gate C22 is connected to the overcurrent protection terminal 10;

The other way of the pin P1.3 of the single-chip controller 2 is connected with the second pin of the NOR gate D23, and the other way of the pin P1.2 of the single-chip controller 2 is passed through the inverter and the second pin of the NOR gate D23 The three pins are connected, and the first pin of the NOR gate D23 is connected with the overcurrent protection terminal 10;

One of the pins P1.4 of the single-chip controller 2 is connected with the second pin of the NOR gate E24, and the other is connected with the third pin of the NOR gate F25 through the inverter. One path of the pin P1.5 is connected to the third pin of the NOR gate E24 through the inverter, and the first pin of the NOR gate E24 is connected to the overcurrent protection terminal 10;

One of the pins P1.5 of the single-chip controller 2 is connected with the second pin of the NOR gate F25, and the other is connected with the third pin of the NOR gate E24 through the inverter. The other path of the pin P1.4 is connected to the third pin of the NOR gate F25 through the inverter, and the first pin of the NOR gate F25 is connected to the overcurrent protection terminal 10;

The output ends of the NOR gate A20, the NOR gate B21, the NOR gate C22, the NOR gate D23, the NOR gate E24 and the NOR gate F25 are respectively connected to the bases of the insulated gate bipolar transistors through inverters , is the control signal output by the computer.

The AB phase-line voltages of the insulated gate bipolar transistor IGBT inverter bridge 4 of the described elevator high-power electronic energy-saving device are connected with the IGBT insulated gate bipolar transistors T1, T2, T3, T4 respectively; T1 and T4 are turned on at the moment of 60 degree phase, T1 and T4 are cut off at the moment of 120 degree phase of AB phase line voltage; T2, T3 end;

The BC phase-to-line voltages of the insulated gate bipolar transistor IGBT inverter bridge 4 are respectively connected to the IGBT insulated gate bipolar transistors T3, T4, T5, and T6; at the 60-degree phase moment of the BC phase-to-line voltage, T3 , T6 is turned on, and T3 and T6 are cut off at 120-degree phase of BC phase-line voltage; T4 and T5 are turned on at 240-degree phase of BC phase-line voltage, and T4 and T5 are cut off at 300-degree phase of BC phase-line voltage;

The CA phase-line voltages of the insulated gate bipolar transistor IGBT inverter bridge 4 are respectively connected to the IGBT insulated gate bipolar transistors T5, T6, T1, and T2; at the 60-degree phase moment of the CA phase line voltage, T5 , T2 conduction, CA phase line voltage 120 degree phase moment makes T5, T2 cut off; CA phase line voltage 240 degree phase time moment makes T6, T1 conduction, CA phase line voltage 300 degree phase time moment makes T6, T1 cut off.

The single-chip controller 2 of the high-power electronic energy-saving device of the elevator is a 51 series single-chip microprocessor 89C52.

The working principle of the utility model is:

During the operation of the elevator, due to the weight of the elevator system, deceleration and braking during operation, about half of the time does not consume electric energy. The kinetic energy and potential energy of the elevator are converted into electric energy by the motor and stored in the DC side capacitor of the inverter. This part of energy is usually converted into heat energy by energy consumption resistance and wasted; the utility model successfully sends this part of energy back to the grid for reuse.

The power inverter controller used in the utility model is composed of three bridge arms and six IGBTs (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor). The input signal is a control signal from the single-chip controller, and its output is respectively connected with the three-phase AC power line of the AC grid. That is, the three phases A, B, and C of the three-phase AC power grid are connected to an IGBT bridge arm respectively. The six IGBTs are turned on at intervals of a certain angle, converting direct current into alternating current at 50 cycles per second, and then sending it back to the grid.

The input signal of the synchronous circuit is the line voltage of the three-phase power grid, which is converted into a pulse signal by the detection conversion circuit, and then the pulse signal is sent to the single-chip controller to realize that the phase of the three-phase AC voltage of the inverter is the same as that of the three-phase AC voltage of the power grid.

The single-chip microcomputer controller of the utility model adopts a 51-series single-chip microprocessor 89C52, plus a logic circuit to form a control system, and controls the inverter bridge IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) to make it follow the prescribed It is required to be turned on and off to complete the inverter from DC voltage to three-phase AC voltage. The input signals of the single-chip controller 2 include three-phase synchronous signals and overcurrent and overvoltage protection signals, and the output signals are control signals for turning on and off the six IGBTs of the inverter controller. A three-phase AC voltage control signal sequence is generated by a single-chip controller, and a system protection signal is generated.

The input signal of the logic protection circuit is the overcurrent, overvoltage and overheating signals of IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor). Change the conduction of the controller.

Please refer to the accompanying drawings 2 and 3, explaining:

1). In Figure 2, ①, ②, ③, ④, ⑤, and ⑥ are the control signals output by the computer, which are sent to the IGBTs (InsulatedGate Bipolar Transistor, InsulatedGate Bipolar Transistor, Insulated Gate Bipolar Transistor) high power transistor.

2). Ud in Figure 3 is the regenerative DC voltage on the DC side of the inverter.

3). In Figure 3, A, B, and C are respectively connected to the three-phase voltage of AC grid A, B, and C.

System features of the utility model:

1). This utility model can feed the regenerative electric energy of the elevator back to the AC grid;

2).A 89C52 single-chip microcomputer is used to generate the inverter control signal and perform system protection;

3). Take the grid line voltage as the object to directly control;

4). The DC side voltage of the inverter is converted as the power supply for the control circuit;

5). With over-voltage, over-current, over-heat safety protection.

Claims (4)

1. A high-power electronic energy-saving device for an elevator, which has a filter, a rectifier, a frequency converter, a motor, a power supply, a logic circuit and a single-chip microcomputer, and is characterized in that: the device at least includes: Logic protection (1) module, microcontroller controller (2), elevator regenerative DC power supply (3), insulated gate bipolar transistor IGBT inverter bridge (4), AC grid (5) and synchronous detection (6) modules are combined into An electronic energy-saving device for an inverter synchronous circuit; The output end of a logic protection (1) module is connected with the input end of the single-chip controller (2) module, and the output end of the single-chip controller (2) module is connected with the IGBT inverter bridge (4) module The input terminals are connected, one output terminal of the insulated gate bipolar transistor IGBT inverter bridge (4) module is connected with the input terminal of the logic protection (1) module, and the other output terminal is connected with the input terminal of the AC grid (5) module connected; The output terminal of an elevator regenerative DC power supply (3) module is connected with the input terminal of the insulated gate bipolar transistor IGBT inverter bridge (4) module; An output end of the AC network (5) module is connected with an input end of the single-chip controller (2) module after passing through the synchronous detection (6) module. 2. The high-power electronic energy-saving device for elevators according to claim 1, characterized in that: the input signals of the computer control and logic protection circuit of the single-chip controller (2) include three-phase synchronous signals and overcurrent and overvoltage protection signals , the output signal is the turn-on and turn-off control signal of the six IGBTs of the inverter controller, where: One of the pins P1.0 of the single-chip controller (2) is connected with the second pin of the NOR gate A (20), and one of the pins P1.1 of the single-chip controller (2) passes through the inverter and or The third pin of the NOT gate A (20) is connected, and the first pin of the NOR gate A (20) is connected with the overcurrent protection (10) end; The other way of the pin P1.1 of the single-chip controller (2) is connected with the second pin of the NOR gate B (21), and the other way of the pin P1.0 of the single-chip controller (2) is through the inverter Be connected with the third pin of NOR gate B (21), the first pin of NOR gate B (21) is connected with overcurrent protection (10) end; One of the pins P1.2 of the single-chip controller (2) is connected with the second pin of the NOR gate C (22), and the other is connected with the third pin of the NOR gate D (23) through the inverter. One way of the pin P1.3 of the single-chip controller (2) is connected with the third pin of the NOR gate C (22) through the inverter, and the first pin of the NOR gate C (22) is connected with the third pin of the NOR gate C (22). The flow protection (10) ends are connected; The other way of the pin P1.3 of the single-chip controller (2) is connected with the second pin of the NOR gate D (23), and the other way of the pin P1.2 of the single-chip controller (2) is through the inverter Be connected with the third pin of NOR gate D (23), the first pin of NOR gate D (23) is connected with overcurrent protection (10) end; One of the pins P1.4 of the single-chip controller (2) is connected with the second pin of the NOR gate E (24), and the other is connected with the third pin of the NOR gate F (25) through the inverter. One way of the pin P1.5 of the single-chip controller (2) is connected with the third pin of the NOR gate E (24) through the inverter, and the first pin of the NOR gate E (24) is connected with the third pin of the NOR gate E (24). The flow protection (10) ends are connected; One of the pins P1.5 of the single-chip controller (2) is connected with the second pin of the NOR gate F (25), and the other is connected with the third pin of the NOR gate E (24) through the inverter. Connect, another way of the pin P1.4 of the microcontroller controller (2) is connected with the third pin of the NOR gate F (25) through the inverter, and the first pin of the NOR gate F (25) is connected with Overcurrent protection (10) terminals are connected; The output terminals of NOR gate A (20), NOR gate B (21), NOR gate C (22), NOR gate D (23), NOR gate E (24) and NOR gate F (25) are all The inverters are respectively connected to the bases of the insulated gate bipolar transistors, and are the control signals output by the computer. 3. The high-power electronic energy-saving device for elevators according to claim 1, characterized in that: the AB phase-line voltages of the IGBT inverter bridge (4) of the insulated gate bipolar transistor (4) are respectively the same as T1, T2, T3, and T4 are connected; T1 and T4 are turned on when the AB phase voltage is 60 degrees, and T1 and T4 are cut off when the AB phase voltage is 120 degrees; AB phase voltage is 240 degrees. T2 and T3 are turned on, and T2 and T3 are cut off at the 300-degree phase moment of the AB phase line voltage; The BC phase-to-line voltages of the insulated gate bipolar transistor IGBT inverter bridge (4) are connected to the IGBT insulated gate bipolar transistors T3, T4, T5, and T6 respectively; when the phase of the BC phase to line voltage is 60 degrees, the Turn on T3 and T6, cut off T3 and T6 at 120-degree phase of BC phase-line voltage; turn on T4 and T5 at 240-degree phase of BC phase-line voltage, and cut off T4 and T5 at 300-degree phase of BC phase-line voltage; The CA phase-line voltages of the insulated gate bipolar transistor IGBT inverter bridge (4) are respectively connected to the IGBT insulated gate bipolar transistors T5, T6, T1, and T2; at the 60-degree phase moment of the CA phase-line voltage Turn on T5 and T2, cut off T5 and T2 at 120-degree phase of CA phase-line voltage; turn on T6 and T1 at 240-degree phase of CA phase-line voltage, and cut off T6 and T1 at 300-degree phase of CA phase-line voltage. 4. The high-power electronic energy-saving device for elevators according to claim 1, characterized in that: the single-chip controller (2) is a 51-series single-chip microprocessor 89C52.

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