Bidirectional elevator energy recovery multi-level converter

Abstract

The utility model relates to a bidirectional elevator energy recovery multi-level converter which comprises a first direct-current voltage source, a second direct-current voltage source and a third direct-current voltage source which are sequentially connected in series, a first direct-current bus capacitor, a second direct-current bus capacitor and a third direct-current bus capacitor which are sequentially connected in series, and the first direct-current voltage source is connected with the first direct-current bus capacitor in parallel. The second direct-current voltage source is connected with a second direct-current bus capacitor in parallel, the third direct-current voltage source is connected with a third direct-current bus capacitor in parallel, the anode end of the first direct-current voltage source is connected with the direct-current bus anode P end, and the cathode end of the third direct-current voltage source is connected with the direct-current bus cathode N end. The direct-current bus positive pole P end and the direct-current bus negative pole N end are connected with the input ends of the A-phase converter, the B-phase converter and the C-phase converter correspondingly, and the output ends of the A-phase converter, the B-phase converter and the C-phase converter are connected with an elevator system motor. According to the utility model, the voltage and current control precision is high, and high-precision speed regulation of the motor in the elevator dragging system can be realized.

Description

Technical Field

[0001] The utility model relates to a multi-level converter for bidirectional elevator energy recovery. Background Art

[0002] A high-performance elevator converter is extremely crucial for an elevator control system. First, the voltage and current control accuracy of the elevator converter should be high, and high-precision speed regulation of the motor in the elevator drive system should be achieved. Second, the elevator converter should achieve high-efficiency power conversion and reduce its own losses. Third, the elevator converter should be able to achieve bidirectional power flow, that is, power can flow from the DC side to the AC side and also from the AC side to the DC side. In this way, the motor can be driven to work in the electric state, and energy can also be fed back to the power grid when the motor is in the generating state, achieving the purpose of energy conservation and emission reduction.

[0003] If a traditional diode uncontrolled rectifier topology is adopted for the elevator converter, precise control of voltage and current cannot be achieved, and bidirectional energy flow cannot be realized.

[0004] In addition, if a traditional two-level silicon-based fully controlled device converter is adopted, the number of output voltage levels is small, the control accuracy of voltage and current is low, and the device loss is high and the efficiency is low.

[0005] Therefore, there is an urgent need to propose an elevator energy recovery converter that can achieve bidirectional energy flow, high voltage and current control accuracy, and high efficiency. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a high-efficiency bidirectional elevator energy recovery multi-level converter based on SiC MOSFET (silicon carbide metal oxide semiconductor field effect transistor) to overcome the existing defects. It has high voltage and current control accuracy and can achieve high-precision speed regulation of the motor in the elevator drive system.

[0007] The technical solution to achieve the above purpose is as follows:

[0008] Bidirectional elevator energy recovery multilevel converter, comprising: a first DC voltage source, a second DC voltage source, a third DC voltage source, a first DC bus capacitor, a second DC bus capacitor, a third DC bus capacitor, and three completely symmetrical phase converters, namely, phase A converter, phase B converter, and phase C converter. The first DC voltage source, the second DC voltage source, and the third DC voltage source are connected in series in sequence. The first DC bus capacitor, the second DC bus capacitor, and the third DC bus capacitor are connected in series in sequence. The first DC voltage source is connected in parallel with the first DC bus capacitor. The second DC voltage source is connected in parallel with the second DC bus capacitor. The third DC voltage source is connected in parallel with the third DC bus capacitor. The positive terminal of the first DC voltage source is connected to the positive P terminal of the DC bus. The negative terminal of the third DC voltage source is connected to the negative N terminal of the DC bus. Both the positive P terminal and the negative N terminal of the DC bus are respectively connected to the input terminals of the phase A converter, the phase B converter, and the phase C converter. The output terminals of the phase A converter, the phase B converter, and the phase C converter are all connected to the elevator system motor.

[0009] Preferably, the connection modes of the phase A converter, the phase B converter, and the phase C converter are completely the same. Then, the phase A converter includes: a first SiC MOSFET, a second SiC MOSFET, a third SiC MOSFET, a fourth SiC MOSFET, a fifth SiC MOSFET, and a sixth SiC MOSFET.

[0010] The positive terminal of the first DC voltage source is respectively connected to the drain terminal of the first SiC MOSFET and the cathode terminal of the first silicon carbide Schottky diode through the positive P terminal of the DC bus.

[0011] The source terminal of the first SiC MOSFET is respectively connected to the anode terminal of the second silicon carbide Schottky diode and one end of the first isolation inductor.

[0012] The anode terminal of the first silicon carbide Schottky diode is respectively connected to the anode terminal of the fourth silicon carbide Schottky diode and one end of the third isolation inductor.

[0013] The positive terminal of the second DC voltage source is respectively connected to the source terminal of the second SiC MOSFET and the anode terminal of the third silicon carbide Schottky diode through point O1.

[0014] The drain terminal of the second SiC MOSFET is connected to the cathode terminal of the second silicon carbide Schottky diode.

[0015] The cathode terminal of the third silicon carbide Schottky diode is connected to the drain terminal of the third SiC MOSFET.

[0016] The other end of the first isolation inductor is connected to one end of the second isolation inductor and the fifth isolation inductor;

[0017] The other end of the second isolation inductor is respectively connected to the source terminal of the third SiC MOSFET and the cathode terminal of the sixth silicon carbide Schottky diode;

[0018] The other end of the third isolation inductor is respectively connected to one end of the fourth isolation inductor and the sixth isolation inductor;

[0019] The other end of the fourth isolation inductor is respectively connected to the source terminal of the fifth SiC MOSFET and the drain terminal of the sixth SiC MOSFET;

[0020] The positive terminal of the third DC voltage source is connected to the source terminal of the fourth SiC MOSFET and the positive terminal of the fifth silicon carbide Schottky diode through point O2;

[0021] The negative terminal of the third DC voltage source is connected to the positive terminal of the sixth silicon carbide Schottky diode and the source terminal of the sixth SiC MOSFET through the negative terminal N of the DC bus;

[0022] The drain terminal of the fourth SiC MOSFET is connected to the cathode terminal of the fourth silicon carbide Schottky diode;

[0023] The cathode terminal of the fifth silicon carbide Schottky diode is connected to the drain terminal of the fifth SiC MOSFET;

[0024] The other ends of the fifth isolation inductor and the sixth isolation inductor are both connected to the elevator system motor.

[0025] Preferably, the other end of the first isolation inductor is connected to one end of the second isolation inductor and the fifth isolation inductor through point X a1 ;

[0026] The positive terminal of the first silicon carbide Schottky diode is connected to the positive terminal of the fourth silicon carbide Schottky diode and one end of the third isolation inductor through point X a2 ;

[0027] Preferably, the other end of the third isolation inductor is connected to one end of the fourth isolation inductor and the sixth isolation inductor through point X a3 ;

[0028] The other end of the fourth isolation inductor is connected to the source terminal of the fifth SiC MOSFET and the drain terminal of the sixth SiC MOSFET through point X a4 ;

[0029] Preferably, the other ends of the fifth isolation inductor and the sixth isolation inductor are connected to the elevator system motor through point X. a5

[0030] Preferably, the current paths of the bidirectional elevator energy recovery multilevel converter include but are not limited to:

[0031] The first SiC MOSFET tube - the first isolation inductor - the fifth isolation inductor - the elevator system motor;

[0032] The third silicon carbide Schottky diode - the third SiC MOSFET tube - the second isolation inductor - the first isolation inductor - the fifth isolation inductor - the elevator system motor;

[0033] The fifth silicon carbide Schottky diode - the fifth SiC MOSFET tube - the fourth isolation inductor - the sixth isolation inductor - the elevator system motor;

[0034] The sixth SiC MOSFET tube - the fourth isolation inductor - the sixth isolation inductor - the elevator system motor.

[0035] The beneficial effects of the present utility model are as follows:

[0036] 1) For the bidirectional elevator energy recovery multilevel converter proposed by the present utility model, the voltage and current control accuracy is high, and high-precision speed regulation of the motor in the elevator drive system can be achieved;

[0037] 2) For the bidirectional elevator energy recovery multilevel converter proposed by the present utility model, its own losses can be reduced, and high-efficiency power conversion can be achieved;

[0038] 3) For the bidirectional elevator energy recovery multilevel converter proposed by the present utility model, bidirectional power flow can be realized, and power can flow from the DC side to the AC side and also from the AC side to the DC side. In this way, the motor can be driven to work in the electric state, and energy can also be fed back to the power grid when the motor is in the generating state, achieving the purpose of energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is the circuit diagram of the bidirectional elevator energy recovery multilevel converter of the present utility model;

[0040] Figure 2 is the schematic diagram of current path 1 of the bidirectional elevator energy recovery multilevel converter in the present utility model;

[0041] Figure 3 is the schematic diagram of current path 2 of the bidirectional elevator energy recovery multilevel converter in the present utility model;

[0042] Figure 4It is a schematic diagram of current path 3 of the bidirectional elevator energy recovery multilevel converter in the present utility model;

[0043] Figure 5 It is a schematic diagram of current path 4 of the bidirectional elevator energy recovery multilevel converter in the present utility model. Detailed implementation manners

[0044] Next, the technical solutions of the present utility model will be described clearly and completely in conjunction with the accompanying drawings. In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0045] Next, the present utility model will be further described in conjunction with the accompanying drawings.

[0046] As Figure 1 shown, the bidirectional elevator energy recovery multilevel converter is characterized by including: a first DC voltage source V dc1 , a second DC voltage source V dc2 , a third DC voltage source V dc3 , a first DC bus capacitor C dc1 , a second DC bus capacitor C dc2 , a third DC bus capacitor C dc3 , and three completely symmetrical phase converters, namely, phase A converter, phase B converter, and phase C converter. The first DC voltage source V dc1 , the second DC voltage source V dc2 , and the third DC voltage source V dc3 are connected in series in sequence. The first DC bus capacitor C dc1 , the second DC bus capacitor C dc2 , and the third DC bus capacitor C dc3 are connected in series in sequence. The first DC voltage source V dc1 is connected in parallel with the first DC bus capacitor C dc1 . The second DC voltage source Vdc2 is connected in parallel with the second DC bus capacitor Cdc2. The third DC voltage source Vdc3 is connected in parallel with the third DC bus capacitor Cdc3. The positive terminal of the anode of the first DC voltage source V dc1 is connected to the positive P terminal of the DC bus. The positive terminal of the anode of the third DC voltage source V dc3The negative electrode end is connected to the negative terminal N of the DC bus. The positive terminal P and the negative terminal N of the DC bus are respectively connected to the input ends of the phase A converter, the phase B converter, and the phase C converter. The output ends of the phase A converter, the phase B converter, and the phase C converter are all connected to the elevator system motor M.

[0047] In the embodiment, the first SiC MOSFET Q a1 , the second SiC MOSFET Q a2 , the third SiC MOSFET Q a3 , the fourth SiC MOSFET Q a4 , the fifth SiC MOSFET Q a5 and the sixth SiC MOSFET Q a6 have small switching losses and low on-state losses, and can effectively improve the efficiency of the elevator converter.

[0048] As Figure 1 shown, the connection methods of the phase A converter, the phase B converter, and the phase C converter are exactly the same. Then, the phase A converter includes: the first SiC MOSFET Q a1 , the second SiC MOSFET Q a2 , the third SiC MOSFET Q a3 , the fourth SiC MOSFET Q a4 , the fifth SiC MOSFET Q a5 and the sixth SiC MOSFET Q a6 . The anode end of the first DC voltage source V dc1 is respectively connected to the drain end of the first SiC MOSFET Q a1 and the cathode end of the first silicon carbide Schottky diode D a1 through the positive terminal P of the DC bus; the source end of the first SiC MOSFET Q a1 is respectively connected to the anode end of the second silicon carbide Schottky diode D a2 and one end of the first isolation inductor L1; the anode end of the first silicon carbide Schottky diode D a1 is respectively connected to the anode end of the fourth silicon carbide Schottky diode D a4 and one end of the third isolation inductor L3; the anode end of the second DC voltage source V dc2 is respectively connected to the source end of the second SiC MOSFET Q a2 and the anode end of the third silicon carbide Schottky diode D a3 through the point O1; the drain end of the second SiC MOSFET Q a2 is connected to the cathode end of the second silicon carbide Schottky diode D a2 ; the anode end of the third silicon carbide Schottky diode D a3The negative electrode end of is connected to the third SiC MOSFET Q a3 The drain electrode end; the other end of the first isolation inductor L1 is connected to one end of the second isolation inductor L2 and the fifth isolation inductor L5; the other end of the second isolation inductor L2 is respectively connected to the third SiC MOSFET Q a3 The source electrode end and the sixth silicon carbide Schottky diode D a6 The negative electrode end; the other end of the third isolation inductor L3 is respectively connected to one end of the fourth isolation inductor L4 and the sixth isolation inductor L6; the other end of the fourth isolation inductor L4 is respectively connected to the fifth SiC MOSFET Q a5 The source electrode end and the sixth SiC MOSFET Q a6 The drain electrode end; the positive electrode end of the third DC voltage source V dc3 The anode end is connected to the source electrode end of the fourth SiC MOSFET Q and the fifth silicon carbide Schottky diode D respectively through point O2 a4 The anode end; the positive electrode end of the third DC voltage source V a5 The negative electrode end is connected to the anode end of the sixth silicon carbide Schottky diode D and the source electrode end of the sixth SiC MOSFET Q respectively through the negative terminal N of the DC bus dc3 The anode end; the drain electrode end of the fourth SiC MOSFET Q a6 The negative electrode end is connected to the anode end of the fourth silicon carbide Schottky diode D a6 The source electrode end; the drain electrode end of the fifth silicon carbide Schottky diode D a4 The negative electrode end is connected to the fifth SiC MOSFET Q a4 The negative electrode end; the drain electrode end of the fifth SiC MOSFET Q a5 The negative electrode end is connected to the drain electrode end of the fifth SiC MOSFET Q a5 The other ends of the fifth isolation inductor L5 and the sixth isolation inductor L6 are both connected to the elevator system motor M.

[0049] In the embodiment, the other end of the first isolation inductor L1 is connected to one end of the second isolation inductor L2 and the fifth isolation inductor L5 through point X a1 Point; the anode end of the first silicon carbide Schottky diode D a1 The anode end is connected to the anode end of the fourth silicon carbide Schottky diode D and one end of the third isolation inductor L3 through point X a2 Point; the anode end of the fourth silicon carbide Schottky diode D a4 Point and one end of the third isolation inductor L3 are connected.

[0050] In the embodiment, the other end of the third isolation inductor L3 is connected to one end of the fourth isolation inductor L4 and the sixth isolation inductor L6 through point X a3 Point; the other end of the fourth isolation inductor L4 is connected to the source electrode end of the fifth SiC MOSFET Q and the drain electrode end of the sixth SiC MOSFET Q through point X a4 Point; the source electrode end of the fifth SiC MOSFET Q a5 Point and the drain electrode end of the sixth SiC MOSFET Q a6 Point are connected.

[0051] In the embodiment, the other ends of the fifth isolation inductor L5 and the sixth isolation inductor L6 are connected to the elevator system motor M through point X. a5

[0052] In the embodiment, the proposed bidirectional elevator energy recovery multilevel converter realizes the conversion control of electric energy through the switching of different current paths. The current paths of the bidirectional elevator energy recovery multilevel converter include but are not limited to:

[0053] As Figure 2 shown, the first SiC MOSFET Q a1 - the first isolation inductor L1 - the fifth isolation inductor L5 - the elevator system motor M;

[0054] As Figure 3 shown, the third silicon carbide Schottky diode D a3 - the third SiC MOSFET Q a3 - the second isolation inductor L2 - the first isolation inductor L1 - the fifth isolation inductor L5 - the elevator system motor M;

[0055] As Figure 4 shown, the fifth silicon carbide Schottky diode D a5 - the fifth SiC MOSFET Q a5 - the fourth isolation inductor L4 - the sixth isolation inductor L6 - the elevator system motor M;

[0056] As Figure 5 shown, the sixth SiC MOSFET Q a6 - the fourth isolation inductor L4 - the sixth isolation inductor L6 - the elevator system motor M.

[0057] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Bidirectional elevator energy recovery multi-level converter, characterized in that: include: The first DC voltage source (V dc1 ), the second DC voltage source (V dc2 ), the third DC voltage source (V dc3 )、The first DC bus capacitor (C dc1 )、The second DC bus capacitor (C dc2 )、The third DC bus capacitor (C dc3 ) and three completely symmetrical phase converters, namely, phase A converter, phase B converter and phase C converter, the first DC voltage source (V dc1 ), the second DC voltage source (V dc2 ) and a third DC voltage source (V dc3 ) are connected in series, the first DC bus capacitor (C dc1 )、The second DC bus capacitor (C dc2 ) and the third DC bus capacitor (C dc3 ) are connected in series, the first DC voltage source (V dc1 ) in parallel with the first DC bus capacitor (C dc1 ), the second DC voltage source (Vdc2) is connected in parallel with the second DC bus capacitor (Cdc2), the third DC voltage source (Vdc3) is connected in parallel with the third DC bus capacitor (Cdc3), the first DC voltage source (V dc1 ) is connected to the positive terminal of the DC bus P, and the third DC voltage source (V dc3 ) The cathode end is connected to the negative N end of the DC bus, the positive P end of the DC bus and the negative N end of the DC bus are respectively connected to the input ends of the A-phase converter, the B-phase converter and the C-phase converter, and the output ends of the A-phase converter, the B-phase converter and the C-phase converter are all connected to the elevator system motor (M).

2. The bidirectional elevator energy recovery multilevel converter according to claim 1, characterized in that: The connection modes of the A-phase converter, the B-phase converter and the C-phase converter are completely the same. Then, the A-phase converter includes: a first SiC MOSFET tube (Q a1 ), the second SiC MOSFET tube (Q a2 ), the third SiC MOSFET tube (Q a3 ), the fourth SiC MOSFET tube (Q a4 ), the fifth SiC MOSFET tube (Q a5 ) and the sixth SiC MOSFET tube (Q a6 ), The first DC voltage source (V dc1 ) are connected to the first SiCMOSFET tube (Q a1 ) of the drain terminal and the first SiC Schottky diode (D a1 ) at the cathode end; The first SiC MOSFET tube (Q a1 ) are connected to the source terminals of the second silicon carbide Schottky diodes (D a2 ) and one end of the first isolation inductor (L1); The first silicon carbide Schottky diode (D a1 ) are connected to the anode terminals of the fourth silicon carbide Schottky diode (D a4 ) and one end of the third isolation inductor (L3); The second DC voltage source (V dc2 ) are connected to the anode end of the second SiC MOSFET tube (Q a2 ) source terminal and the third SiC Schottky diode (D a3 ) at the anode end; The second SiC MOSFET tube (Q a2 ) is connected to the drain terminal of the second SiC Schottky diode (D a2 ) at the cathode end; The third silicon carbide Schottky diode (D a3 ) is connected to the cathode terminal of the third SiC MOSFET (Q a3 ) of the drain terminal; The other end of the first isolation inductor (L1) is connected to one end of the second isolation inductor (L2) and the fifth isolation inductor (L5); The other end of the second isolation inductor (L2) is connected to the third SiC MOSFET tube (Q a3 ) source terminal and the sixth SiC Schottky diode (D a6 ) at the cathode end; The other end of the third isolation inductor (L3) is respectively connected to one end of the fourth isolation inductor (L4) and one end of the sixth isolation inductor (L6); The other end of the fourth isolation inductor (L4) is connected to the fifth SiC MOSFET tube (Q a5 ) and the source terminal of the sixth SiC MOSFET tube (Q a6 ) of the drain terminal; The third DC voltage source (V dc3 ) anode terminals are connected to the fourth SiC MOSFET tube (Q a4 ) source terminal and the fifth SiC Schottky diode (D a5 ) at the anode end; The third DC voltage source (V dc3 ) The cathode end is connected to the sixth silicon carbide Schottky diode (D a6 ) and the anode terminal of the sixth SiC MOSFET tube (Q a6 )’s source terminal; The fourth SiC MOSFET tube (Q a4 ) is connected to the drain terminal of the fourth SiC Schottky diode (D a4 ) at the cathode end; The fifth silicon carbide Schottky diode (D a5 ) is connected to the cathode terminal of the fifth SiC MOSFET (Q a5 ) of the drain terminal; The other ends of the fifth isolation inductor (L5) and the sixth isolation inductor (L6) are both connected to the elevator system motor (M).

3. The bidirectional elevator energy recovery multilevel converter according to claim 2, characterized in that: The other end of the first isolation inductor (L1) is connected to a1 The point is connected to one end of the second isolation inductor (L2) and the fifth isolation inductor (L5); The first silicon carbide Schottky diode (D a1 ) through the anode end of X a2 point and the fourth SiC Schottky diode (D a4 ) is connected to the anode terminal of the first isolation inductor (L3).

4. The bidirectional elevator energy recovery multilevel converter according to claim 2, characterized in that: The other end of the third isolation inductor (L3) is connected through X a3 The point is connected to one end of the fourth isolation inductor (L4) and the sixth isolation inductor (L6); The other end of the fourth isolation inductor (L4) is connected to the a4 point with the fifth SiC MOSFET tube (Q a5 ) and the source terminal of the sixth SiC MOSFET tube (Q a6 )’s drain terminal connection.

5. The bidirectional elevator energy recovery multilevel converter according to claim 2, characterized in that: The other ends of the fifth isolation inductor (L5) and the sixth isolation inductor (L6) are connected through X a5 The point is connected with the elevator system motor (M).

6. The bidirectional elevator energy recovery multilevel converter according to claim 2, characterized in that: The current path of the bidirectional elevator energy recovery multilevel converter includes but is not limited to: The first SiC MOSFET tube (Q a1 )-first isolation inductor (L1)-fifth isolation inductor (L5)-elevator system motor (M); The third silicon carbide Schottky diode (D a3 )-Third SiC MOSFET tube (Q a3 )-second isolation inductor (L2)-first isolation inductor (L1)-fifth isolation inductor (L5)-elevator system motor (M); The fifth silicon carbide Schottky diode (D a5 )-Fifth SiC MOSFET tube (Q a5 )-fourth isolation inductor (L4)-sixth isolation inductor (L6)-elevator system motor (M); The sixth SiC MOSFET tube (Q a6 )-a fourth isolation inductor (L4)-a sixth isolation inductor (L6)-an elevator system motor (M).

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