Wireless Charger 3.0

Wireless Charging

By the nature of physics, the Wireless Charger 3.0 is free of any mechanical wear and tear related to the power transfer, such as charging contacts. So, there is no maintenance on this.

As dirt and debris are present in almost all industrial environments and other thinkable operation theaters of Wireless Charger, we try to limit exposure and impacts. We do not move air through power electronics units for cooling purposes, so no maintenance requirements for cleaning. We do cool only on the basis of passive convection cooling. The absence of fans, having a limited lifetime, eliminates consideration of maintenance on this, as well as eliminating fans as potential root causes for downtime. The permanent monitoring of operational states on the power electronic units provides us with the option to not only detect fault states and active protection modes, but also allows us to trigger warnings and start appropriate actions before downtime becomes effective and costs money. The IPS (Inductive Power Supply unit) and the Pads do have high IP ratings, making cleaning easy going, if needed at all.

The Wireless Charger 3.0 is designed to be easy to handle, very robust, widely unaffected by ambient conditions, free of mechanical wear and tear, and requires a minimum of attention after commissioning; if it needs attention, it raises for attention itself. The minimum attention required, the absence of mechanical wear and tear, and the easy action in case make Wireless Chargers a truly maintenance-friendly solution with excellent total cost of ownership. So Wireless Charger 3.0 pays back steadily over time.

Advantages and features of Wireless Charger 3.0:

In-process Charging / Opportunity Charging:
No downtime, no extra vehicles, smaller batteries.

Intervention-free charging:
The charging process can be fully automated, and human intervention is not necessary.

Ambient Influences and Safety:
There are no open contact surfaces that can be affected by ambient influences. The system is touch-proof, so it has a high level of safety. Components typically exposed come in IP54 or higher.

Clear and easy to understand displays and interfaces:
Operator ease by LEDs or displays in color, clearly indicating states, and display on the stationary Inductive Power Supply names states. CAN open/CAN 2.0B communication and Ethernet interfaces allow a life monitoring of operational data, access to logged data, and an easy interaction between the Wireless Charger and vehicle side controllers and/or the battery management system.

Large position tolerances:
Wireless Charger is very position-tolerant regarding the coverage of pads.

Specification

Summary of some practical characteristics for the Wireless Charger 3.0

Power:
Power output: 3 kW maximum, and 60 A maximum, and 59 V maximum
Power efficiency: up to 93% output power compared to the mains input power

Positioning tolerances and air gaps:
Air gap tolerance: from 10 to 40 mm for maximum efficiency
Position tolerance: +/- 25 mm for maximum efficiency
Position tolerance: +/- 40 mm depending on air gap size
Angle tolerance: up to 40° with 40 mm spacing

Interaction mobile and stationary sides:
Internal communication: inductive communication, not subject to any radio interference

Interfaces:
External communication: Ethernet, CAN 2.0B/CANopen, with several data matrix available

Programming:
User-friendly web server with four modes of operation

Heat management:
100% passive cooling: electronics without a single fan, for a higher lifetime
Temp. management: Pads and battery temperatures are managed in 2 steps (warning, error)

Inductive Power Supply:
IP54, can be mounted directly on the wall without the extra cost of a cabinet

Physical interface (IPS):
The charging station has a screen and a large status backlighting (to the wall)

Physical interface (MPU):
The mobile electronics has 3 LEDs to facilitate testing and commissioning

Cable lengths:
WirelessCharger 3.0 pad cables can be cut on-site to the desired length

Possible optimisation of MPU size:
MPU size could be made lower by removing the heat sink if alternative cooling is available, or the chassis can be used for heat dissipation. Ask for a specific version if needed.

Downloads

WirelessCharger 3.0 - Program 9200

PDF | 2.94 MB

Language: English-UK

Document type: Brochures

Download

WirelessCharger 3.0 - Powerful | Reliable | Efficient

PDF | 1.04 MB

Language: English-UK

Document type: Brochures

Download

FAQ

How does the charging process work?

Whenever the "Start of charge" conditions are met, Wireless Charger 3.0 starts delivering the current target as set within the chosen mode of operation. The MPU output current ramps up very quickly and runs through the battery, which sets the charging voltage (a low state of charge leads to a smaller internal resistance and to a smaller voltage). The charging voltage is a constant feedback for the charging process, which will let the current reach its target as long as the set voltage threshold is not reached.

Constant Current phase (CC): When the battery is discharged, the MPU delivers the target current, and the charging voltage is set by the battery's internal resistance. When the battery is charged, its internal resistance increases, gradually increasing the measured charging voltage.
Voltage Threshold: This is the pivot point from which it is important to reduce the charging current to limit the charging voltage and not exceed the battery datasheet voltage limit. In many cases, the voltage threshold is approximately the voltage reached at 80% SoC.
Constant Voltage phase (CV): When the battery is charged at more than 80%, the charging voltage is about to go beyond the voltage threshold, then Wireless Charger 3.0 behaves like a voltage regulator and reduces the MPU current output, just as needed, to keep the charging voltage below the voltage threshold. As the charging process keeps on going, the battery's internal resistance keeps on rising. Therefore, Wireless Charger 3.0 keeps on reducing the charging current until a stop condition is met. Charging during the CV phase is slower.

Which settings should I use?

The safest recommended settings are those exchanged directly between a Battery Management System (BMS) and the MPU in the frame of a BMS-only mode of operation: the battery permanently tells the charger what it needs, via CAN communication. Other settings are possible by using other modes of operation. It is important to refer to the battery manufacturer's datasheet and to follow the recommended values for the charging current and the charging voltage: this will preserve the battery life cycle number and will avoid any hazardous situation.

The charging current setting must always be below the maximum charging current value stated in the battery datasheet.
Voltage threshold setting should always be below the maximum voltage value stated in the battery datasheet.
Overvoltage setting should preferably be below the maximum voltage value stated in the battery datasheet, and at a value strictly above the Voltage threshold setting.

How many charging stations do I need?

WirelessCharger 3.0 is based on charging stations compatible with all MPUs, regardless of the types of batteries, vehicles, or selected mode of operation. The same charging station can charge a Li-ion battery right after it has charged a lead-acid battery on a different type of vehicle in the same plant.

The total number of vehicles and their need for recharge should be the only factors considered when evaluating the number of charging stations needed.

There are applications requiring one charging station for each vehicle. Other applications can cope with one charging station for four vehicles. On average, there are two to three vehicles for each charging station.

What kind of communication can be established with the BMS?

The Battery Management System (BMS) is a specific piece of hardware in all Li-ion batteries. It does not exist in lead-acid batteries. It aims at, among other things, balancing and protecting the battery cells and, in most cases, at communicating with the charger so as to get the proper charging current at all SoC levels, avoiding any battery hazard and maximizing the battery life cycle number. The communication of a BMS and a charger is defined by a protocol which goes up to the definition of specific bytes in a set order (e.g., current, then voltage, then SoC, then temperature, etc )

A battery with a CAN 2.0B port might or might not be compatible with Wireless Charger 3.0. CAN 2.0B port: it all depends on the data definition (the data matrix), which should match the ones embedded in the charger. If needed, the BMS data matrix could be updated (please refer to the battery supplier) to match one of the protocol options provided with WirelessCharger 3.0. Alternatively, the BMS can speak to the PLC/VCU via CAN 2.0B so that the PLC/VCU instructs the MPU via Ethernet in PLC-only Mode.

The many options of protocols and the many modes of operations available with Wireless Charger 3.0 grant you the maximum range of options for a suitable charging solution of your own. Should your needs vary from the ones implemented, please do consult us for additional options.

What are the typical charging sequences defined by AGV/AMR integrators?

Full charging: The charging process is performed with few time constraints. It goes through the entire CC and CV charging phases to reach close to 100% SoC at the end of the charging process.

Opportunity charging or "In-Process" charging: Additional charging stations are available to perform charging during a rather short period of time, at quite a high current, when a vehicle is idling between two tasks. The benefits are real with a fast-starting charger like Wireless Charger 3.0, and it is usually preferred for batteries that are not charged to more than 80% SoC.

Intermediate charging: The charging process is set to keep the battery partially charged, as only a fraction of the battery capacity is intended to be used (small Depth of Discharge, or DoD). Charging a battery at less than 80% SoC could significantly improve its life cycle number, but it will require more frequent charging sequences, all in the CC phase with a shorter charging time (compared to the longer charging of the CV phase).

The final choice of the charging sequence(s) depends on many factors related to the application needs and the hardware involved. It is specific to each application type and each vehicle design, but it is mostly a system software management topic.

What are the field and health effects?

There is no magnetic field around a stationary pad as long as it is not facing a mobile pad: this is impossible. Indeed, a condition for WirelessCharger 3.0 to start its operation is the establishment of a communication between the mobile electronics (MPU) and the charging station (IPS), which can be performed only if there is a close proximity of the two pads with a proper alignment. This is a specific safety design of WirelessCharger 3.0, which is independent from any radio system and therefore not subject to any radio interference while in operation.

When power is being transferred, there is a magnetic field around the pads. Our designers are well aware of this, so they worked out a field strength that does not exceed the legal limits and recommendations as given by the ICNIRP (International Commission for Non-Ionizing Radiation) in 2010.

The ICNIRP recommendation is recognized worldwide and the basis for most national legislation and standards. The fields are not to be compared with radio waves as occurring in radio communication or with mobile phones: these are electromagnetic waves designed to be sent out to bridge large distances. It must also be noticed that magnetic fields, as used in Wireless Charger 3.0 as a means for power transfer, are linked to their source, so they are always limited to the very proximity of the pads.

What types of batteries or accumulators can I use?

Most types of batteries can be used with Wireless Charger 3.0 (Lead Acid, Li-ion NMC, Li-ion LFP, etc). Batteries with or without a communication port can be used as well. Accumulators can, of course, be used, as this should be the suitable name to use as we speak of rechargeable energy storage solutions, but generally speaking, the word "battery" is used in the industry. So let’s keep speaking of "batteries" instead of “accumulators”.

A few battery manufacturers restrict the charging possibilities by imposing a communication byte to be activated (via CAN), reducing the operation options to BMS-only Mode or BMS&PLC Mode.