Integrated onboard chargers for plug-in electric vehicles

• US 10,562,404 B1
• Filed: 10/04/2016
• Issued: 02/18/2020
• Est. Priority Date: 10/05/2015
• Status: Active Grant

• Current Assignee: University of Maryland
• Original Assignee: University of Maryland
• Inventors: Khaligh, Alireza, Tang, Yichao, Shi, Chuan
• Primary Examiner(s): Pacheco, Alexis B
• Application Number:
  US15/285,062
• Time in Patent Office: 1,232 Days
• Field of Search: 320107, 320108, 320109
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 50/10 using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines
• CPC Class Codes: B60L 53/24 Using the vehicle's propulsion converter for charging
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/12 Arrangements for reducing harmonics from ac input or output
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 3/1586 switched with a phase shift, i.e. interleaved
• CPC Class Codes: H02M 7/797 using semiconductor devices only
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

An onboard charger for both single-phase (level-1 and level-2, up to 19.2 kW) and three-phase (level-3, above 20 kW) charging of a battery in Plug-in Electric Vehicles (PEVs) is integrated with the Propulsion machine-Inverter Group residing in the PEV, and is controlled to operate in propulsion and battery charging modes. The subject integrated onboard charger provides battery charging at the rated power of the Propulsion machine, does not need motor/inverter rearrangement, does not require additional bulk add-on passive components, provides an effective input current ripple cancellation, and operates without rotation of the Propulsion machine during the steady state charging.

Claims

1. An onboard charger system for a battery in Plug-in Electric Vehicles (PEVs), wherein said onboard charger is operatively coupled to an AC 1-phase grid, comprising:

an onboard charger integrated with at least one Propulsion machine-Inverter Group built with a 3-phase Alternative Current (AC) Propulsion Machine having three phase-terminals and a Propulsion Inverter coupled to an input of said 3-phase AC Propulsion machine, said onboard charger being operatively coupled between a grid supplying AC voltage and a battery to charge said battery at a rated power of said 3-phase AC Propulsion machine,

a controller supplying control signals to said Propulsion Machine-Inverter Group in a predetermined order depending on a required mode of operation of the PEV to attain efficient charging of said battery, wherein said mode of operation includes a propulsion mode of operation and a battery charging mode of operation, and

a diode bridge coupled between said 1-phase grid and said at least one Propulsion Machine-Inverter Group, and between at least one of said three phase-terminals of said Propulsion machine and said Propulsion Inverter,

wherein said Propulsion Inverter has a DC_link operatively coupled to said battery, wherein said diode bridge is coupled to a negative terminal of said DC_link of said Propulsion Inverter, and wherein said 3-phase AC Propulsion Machine has three windings angularly spaced apart 120°

one from another,

wherein in said battery charging mode of operation, said diode bridge operates to rectify said AC voltage supplied by said 1-phase grid, wherein said 3-phase AC Propulsion Machine'"'"'s windings and said Propulsion Inverter are pulse-width-modulation (PWM) switched by said controller to operate as a two-channel interleaved boost converter,

wherein said Propulsion Inverter includes a first leg, a second leg, and a third leg, each leg coupled to a first, second, a third winding of said 3-phase AC Propulsion Machine, respectively,

said first leg including switches S₁ and S₂, and corresponding diodes D₁ and D₂, each coupled in parallel to a respective one of said switches S₁ and S₂, respectively,

said second leg including switches S₃ and S₄, and corresponding diodes D₃ and D₄, each coupled in parallel to a respective one of said switches S₃ and S₄, respectively, and

said third leg including switches S₅ and S₆, and corresponding diodes D₅ and D₆, each coupled in parallel to a respective one of said switches S₅ and S₆, respectively, and wherein said controller operates two of said first, second and third legs in interleaved regime with 180°

phase difference in time domain, wherein said one of switches S₂, S₄, S₆ and one of corresponding diodes D₁, D₃, D₅ form a first channel, and wherein said one of switches S₂, S₄, S₆ and one of corresponding diodes D₁, D₃, D₅ form a second channel of said interleaved boost converter,

wherein said controller PWM switches said two-channel interleaved boost converter in switching sub-modes I, II, III, IV,

wherein, when a duty cycle D of said PWM switching 0<

D<

0.5, said controller switches said two-channel interleaved boost controller in a periodical switching sequence I-III-II-III-I of the switching sub-modes,

wherein, when 0.5<

D<

1, said controller switches said two-channel interleaved boost controller in a periodical switching sequence IV-I-IV-II-IV of said switching sub-modes,

wherein in said switching sub-mode I, said controller turns ON said switch S₄, and turns OFF said switch S₆, and said diode D₅ is in conducting state,

wherein in said switching sub-mode II, said controller switches ON said switch S₆, and turns OFF said switch S₄, and said diode D₃ is in conducting state,

wherein in said switching sub-mode III, said controller turns OFF said switches S₄ and S₆, and said diodes D₃ and D₅ are in conducting state, and

wherein in said switching sub-mode IV, said controller turns ON said switches S₄ and S₆, and reverse biases said diodes D₃ and D₄.

2. An onboard charger system for a battery in Plug-in Electric Vehicles (PEVs), wherein said onboard charger is operatively coupled to an AC 3-phase grid, comprising:

an onboard charger integrated with at least one Propulsion machine-Inverter Group built with a 3-phase Alternative Current (AC) Propulsion Machine having three phase-terminals and a Propulsion Inverter coupled to an input of said 3-phase AC Propulsion machine, said onboard charger being operatively coupled between a grid supplying AC voltage and a battery to charge said battery at a rated power of said 3-phase AC Propulsion machine,

a controller supplying control signals to said Propulsion Machine-Inverter Group in a predetermined order depending on a required mode of operation of the PEV to attain efficient charging of said battery, wherein said mode of operation includes a propulsion mode of operation and a battery charging mode of operation,

a unidirectional AC-DC 3-phase buck-type PWM rectifier coupled between at least one of said three phase-terminals of said Propulsion machine and a negative terminal of the DC_link of said Propulsion Inverter, and

an Electromagnetic Interference (EMI) filter coupled between said 3-phase grid and said 3-phase buck-type PWM rectifier,

wherein said windings of said Propulsion Machine are utilized as a DC-inductor,

wherein said 3-phase buck-type PWM rectifier includes semiconductor switches Q₁, Q₂, Q₃, Q₄, Q₅, Q₆, each switch including a switch selected from a group of unidirectional switches including insulated-gate-bipolar-transistor (IGBT) coupled in series with a freewheeling diode, metal-oxide-semiconductor field-effect-transistors (MOSFETs) coupled in series with a freewheeling diode, silicon-controlled-rectifier (SCR), and combination thereof.

4. The onboard charger system of claim 2, wherein in said propulsion mode of operation, said battery provides propulsion power through said switches S₁-S₆ of said three-phase Propulsion Inverter,

wherein in said battery charging mode of operation, said switches S₁ and S₂ of said Propulsion Inverter connected to a positive terminal of said unidirectional AC-DC 3-phase buck-type PWM rectifier are disabled, wherein D₁ and D₂ are reverse biased, and

wherein said second and third legs containing said S₄ and D₃ and S₆ and D₅, respectively, are controlled in the interleaved regime.

5. The onboard charger system of claim 2, wherein during said battery charging mode of operation, said controller switches said semiconductor switches Q₁-Q₆ in active switching sub-modes I1, I2, I3, I4, I5, I6, and zero-switching sub-modes I0 and I7 in a predetermined order, wherein in each of said switching sub-mode, three out of six semiconductor switches Q₁-Q₆ are turned ON at a time,

wherein during said active switching sub-modes, a DC current flows through respective three switches of said switches Q₁-Q₆ and said 3-phase grid, and said diode D₂ is reverse biased, and

wherein in said zero-switching modes, said 3-phase grid is disconnected from said at least one Propulsion machine-Inverter Group.

6. The onboard charger system of claim 5, wherein said controller PWM switches said onboard charger in switching sub-modes I, II, III, IV,

wherein, when a duty cycle D of said PWM switching 0<

D<

0.5, said controller PFM switches said two-channel interleaved boost controller in a periodical switching sequence I-III-II-III-I of said modes,

wherein, when 0.5<

D<

1, said controller PWM switches said two-channel interleaved boost controller in a periodical switching sequence IV-I-IV-II-IV of said sub-modes,

wherein in said sub-mode I, said controller turns ON said switch S₄, turns OFF said switch S₆, and said diode D₅ is in conducting state,

wherein in said sub-mode II, said controller switches ON said switch S₆, turns OFF said switch S₄, and said diode D₃ is in conducting state,

wherein in said sub-mode III, said controller turns OFF said switches S₄ and S₆, and said diodes D₃ and D₅ are in conducting state, and

wherein in said sub-mode IV, said controller turns ON said switches S₄ and S₆, and reverse biases said diodes D₃ and D₄.

3. An onboard charger system for a battery in Plug-in Electric Vehicles (PEVs), wherein said onboard charger is operatively coupled to an AC 3-phase grid, comprising:

an onboard charger integrated with at least one Propulsion machine-Inverter Group built with a 3-phase Alternative Current (AC) Propulsion Machine having three phase-terminals and a Propulsion Inverter coupled to an input of said 3-phase AC Propulsion machine, said onboard charger being operatively coupled between a grid supplying AC voltage and a battery to charge said battery at a rated power of said 3-phase AC Propulsion machine,

a controller supplying control signals to said Propulsion Machine-Inverter Group in a predetermined order depending on a required mode of operation of the PEV to attain efficient charging of said battery, wherein said mode of operation includes a propulsion mode of operation and a battery charging mode of operation,

a bidirectional AC-AC three-phase buck-boost type PWM rectifier coupled to the Propulsion Machine'"'"'s three phase-terminals, and

an EMI filter coupled between said 3-phase grid and said bi-directional AC-AC three-phase buck-boost type PWM rectifier,

wherein said bi-directional AC-AC three-phase buck-boost type PWM rectifier includes a first leg, a second leg and a third leg, each leg including bi-directional switches selected from a group including a pair of back-to-back connected IGBTs, a pair of back-to-back MOSFETs, bilateral triode thyristors (TRIACs), and combination thereof.

7. The onboard battery charger system of claim 3, wherein during said battery charging mode of operation, said switches S₁-S₆ of said first, second and third legs of said Propulsion Inverter are disabled by said controller, and said corresponding freewheeling diodes D₁-D₆ of said Propulsion Inverter are in conducting state,

wherein said Propulsion machine windings L_a, L_b, L_c, and said freewheeling diodes D₁-D₆ create a three-phase buck-boost AC-DC converter,

wherein the bi-directional switches G₁-G₆ of said first, second and third legs of said buck-boost type PWM rectifier are controlled by said controlled in a number of switching sub-modes in a predetermined order, wherein in each switching sub-mode, respective three out of six switches G₁-G₆ are turned ON,

wherein each of said switching sub-modes includes a respective one of active switching modes I1-I6 to charge a corresponding winding of said Propulsion machine followed by a corresponding one of zero switching modes IO1-IO6 to discharge said corresponding winding of said Propulsion machine,

wherein in said respective active switching sub-mode, one of said back-to-back switches is turned ON, and the diode corresponding to another switch in said two back-to-back switches conducts, thus creating a uni-directional rectifier leg, and

wherein in said corresponding zero switching sub-mode, said switches G₁-G₆ are turned off, and three out of six diodes D₁-D₆ of said Propulsion Inverter conduct.

8. An onboard battery charger system for a battery in Plug-in Electric Vehicles (PEVs), comprising:

an onboard charger integrated with at least one Propulsion machine-Inverter Group built with a 3-phase Alternative Current (AC) Propulsion Machine having three phase-terminals and a Propulsion Inverter coupled to an input of said 3-phase AC Propulsion machine, said onboard charger being operatively coupled between a grid supplying AC voltage and a battery to charge said battery at a rated power of said 3-phase AC Propulsion machine,

a controller supplying control signals to said Propulsion Machine-Inverter Group in a predetermined order depending on a required mode of operation of the PEV to attain efficient charging of said battery, wherein said mode of operation includes a propulsion mode of operation and a battery charging mode of operation, and

a bi-directional DC-DC converter coupled between said Propulsion Inverter and said battery,

wherein said bi-directional DC-DC converter is a converter selected from a group consisting of;

non-isolated converter, isolated converter, non-isolated converter used in said propulsion mode of operation, isolated converter used in said battery charging mode of operation, and combinations thereof.

9. The onboard battery charger system of claim 8, wherein said onboard charger is operatively coupled to at least one grid selected from a group consisting of:

AC 1-phase grid, AC 3-phase grid, and combination thereof.

10. An onboard charger system for a battery in Plug-In Electric Vehicles (PEVs), wherein said onboard charger is operatively coupled to an AC 3-phase grid, comprising:

an onboard charger integrated with at least one Propulsion machine-Inverter Group built with a 3-phase Alternative Current (AC) Propulsion Machine having three phase-terminals and a Propulsion Inverter coupled to an input of said 3-phase AC Propulsion machine, said onboard charger being operatively coupled between a grid supplying AC voltage and a battery to charge said battery at a rated power of said 3-phase AC Propulsion machine, and

a controller supplying control signals to said Propulsion Machine-Inverter Group in a predetermined order depending on a required mode of operation of the PEV to attain efficient charging of said battery, wherein said mode of operation includes a propulsion mode of operation and a battery charging mode of operation.