CONTROL SYSTEM FOR ELECTRIC DRIVE VEHICLES

• US 20080046140A1
• Filed: 08/02/2007
• Published: 02/21/2008
• Est. Priority Date: 08/02/2006
• Status: Abandoned Application

• Current Assignee: Selin Sistemi SPA
• Original Assignee: Selin Sistemi SPA
• Inventors: Lotti, Fabio, Pallottini, Alberto
• Application Number:
  US11/832,659
• Publication Number:
  US 20080046140A1
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 15/06 using substantially sinusoidal ac
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

This invention teaches a control apparatus for electric drive vehicles comprising a low-voltage electric power source (1), a low-voltage inverter (3), a high-frequency transformer (4), a high-voltage inverter (5), a three-phase inverter (6) coupled to an electric motor (7), and a central processing unit (10) coupled to all the other components of the apparatus, means for detecting revolution speed and position of the axis of the motor being provided, and a method to manage the apparatus.

Claims

1. A control apparatus for electric drive vehicles comprising a low-voltage electric power source (1), a low-voltage inverter (3), a high-frequency transformer (4), a high-voltage inverter (5), a three-phase inverter (6) coupled to an electric motor (7), and a central processing unit (10) coupled to all the other components of the apparatus, means for detecting revolution speed and position of the axis of said motor being provided.

2. The apparatus according to claim 1, wherein a chopper (2) is arranged between said low-voltage electric power source (1) and said low-voltage inverter (3), said chopper (2) being coupled to said central processing unit (10).

3. The apparatus according to claim 1, wherein a low-voltage recovering circuit (8) and a high-voltage recovering circuit (9) are provided in the respective portions of the apparatus.

4. The apparatus according to claim 1, wherein one or more capacitive components are arranged between said high-voltage inverter (5) and said three-phase inverter (6).

5. The apparatus according to claim 1, wherein said low-voltage inverter (3) includes two pairs of switches (103, 203, 303, 403), each switch comprising one or more diodes (113) controlled by said central unit (10).

6. The apparatus according to claim 5, wherein said diodes (113) are FETs.

7. The apparatus according to claim 1, wherein said high-frequency transformer (4) is a transformer comprising a planar core and windings on a printed circuit board with a turns ratio from 1:

5 to 1;

12, and preferably of 1;

8.

8. The apparatus according to claim 7, wherein the operating frequency of said transformer (4) is 40 kHz in generator mode, and 50 kHz in motor mode.

9. The apparatus according to claim 1, wherein said high-voltage inverter (5) comprises 600V-IGBTs as switches.

10. The apparatus according to claim 1, wherein said three-phase inverter (6) is coupled to said motor (7) and to a plug (406) which provides an electrical connection to alternating current mains, said three-phase inverter (6) being used as a battery charger through a switch (506), the inductance (107) of said motor (7) being used as an input inductance.

11. A method to manage a control apparatus for electric drive vehicles comprising a low-voltage electric power source (1), a low-voltage inverter (3), a high-frequency transformer (4), a high-voltage inverter (5), a three-phase inverter (6) coupled to an electric motor (7), and a central processing unit (10) coupled to all the other components of the apparatus, means for detecting revolution speed and position of the axis of said motor being provided, said method comprising the steps of:

(a) acquiring data relative to voltage, current intensity and state of charge of the batteries, and acquiring data relative to the axis of the motor;

(b) controlling the voltage output to the motor according to the torque requirement resulting from acquired data; and

(c) adjusting generator operation according to the voltage and current intensity data acquired for the electric power source

12. The method according to claim 11, wherein said step of controlling the voltage output to the motor according to the torque requirement resulting from acquired data comprises the sub-steps of:

(a) determining the value of Vinv_ref according to the relationship;

Vinv_—

ref=1.78*√

(vd_—

n²+vq_—

n²)

which relationship takes in account voltage references vd_n and vq_n;

(b) comparing said value to a reference voltage value;

(c) making the value of Vinv_ref equal to the reference voltage value;

(d) checking the turning-on and checking a request for enabling the motor;

(e) checking the torque requirement of the motor;

(f) checking the axis velocity against a reference spin value;

(g) based on said check, determining if the previously computed reference voltage value for the inverter is greater or lesser than the voltage at the capacitors; and

(h) if Vinv_ref is greater than the voltage at the capacitors, increasing the overlapping of the turning-on intervals for the switches of the inverter;

or if Vinv_ref is not greater than the voltage at the capacitors, reducing the overlapping of the turning-on intervals for the switches of the inverter.