TM4’s new bidirectional charger-inverter

Motor and power electronics manufacturer TM4, a subsidiary of Hydro-Québec, has launched a new bidirectional charger-inverter. TM4’s BCI20 functions as both battery charger and inverter for use in a variety of electric and hybrid vehicle applications. It is designed to use the full current range from the AC mains as defined in SAE J1772 for a maximum charge power of 18 kW at 240 VAC.

When the vehicle is in use, the charger becomes a dual inverter that can provide two independent three-phase outputs of 9 kVA each to power various AC auxiliary loads.

“The charger combined with two inverter outputs simplifies vehicle integration by combining multiple functionalities in one box,” says TM4 Sales and Customer Service Director Eric Azeroual.

The BCI20 satisfies the IP67 rating for reliable operation in harsh under-hood vehicle environments. It’s designed to be very compact and light, allowing for flexible installation in multiple mounting locations.

The Lion Electric Company is using the BCI20 in its electric school buses. “To our knowledge, no other unit on the market offers so many features, such power density, quality and ease of integration at such a competitive cost,” says Lion Director of Engineering Bruno Pilon.

In the future, TM4 aims to expand this product line, offering both single-phase and three-phase bidirectional charger-inverters in 450 VDC and 750 VDC versions.


Source: TM4

  • nordlyst

    The 3-phase 400V version of this should be interesting, and they should make a more compact version designed for 20A current for 22 kW at a lower cost in markets that has the grid to do it (Europe). 18 kW at 240V single-phase means they handle 75A of current, making the device much larger, heavier and pricier than one for 20A. Going much beyond 22 kW is pointless as well since type 2 points for 22 kW are simple and cheap to establish, while those for 44 kW are not (again, in Europe, which has mostly TN network with 400V 3-phase delivered to most buildings, being stepped down to 230 V single-phase in most people’s houses).

    I’m not sure what vehicles that box is intended for, but few people can pull 75 A without very expensive reworking of their electrical installation. Pulling 20A instead and getting 22 kW from it is a much cheaper affair, and since the box itself would also be cheaper as well as smaller and lighter I think they should make a lower-current version…

    Btw I’m not sure it’s 20A! The power, with three-phase current, decreases with the reactance of the load. For a pure resistive load it’s simply 3 * voltage * current, so 3*400V*20A = 24 kW, but the load here definitely isn’t purely resistive so you’d probably need more. No matter; you would need much less than 75A. 32A should cover it. And then the same logic still holds.

    • gasdive

      400V 3phase isn’t ‘stepped down to 230V’. Each phase of the 3phase supply is a 230V single phase. So a 230V single phase household supply is just one phase of a 3phase supply. The “400V” is the potential between phases which are 120 degrees apart. Each phase is only 230V from ground/neutral.

      Equally, the power of a 400V 3phase supply isn’t 3*400V*20A. If you had a 20A 3phase, it would be 3*230V*20A. (13.8 kW) Or as it’s normally expressed: the square root of 3, times the nominal voltage of 400, times the amperage of 20A. (also 13.8 kW). You can rearrange to give you the amperage at a known voltage and power. At 400V a 22kW 3 phase load is drawing 22000W/(400V*sqrt3) or 31.75 Amps, usually nominally called a 32 amp supply.