Load throw-off management
What you'll find here
- What is the Load throw-off function?
- What can it be used for?
- What are the Limitations to the Load throw-off function?
Intro
Given the following context:
- Multiple consumers
- Some consumers require constant electrical supply
- Others have a variable need for electrical supply
The load throw-off feature helps manage the electrical supply distribution in that context.
Following are some example scenarios to help introduce the feature in more detail.
Example scenario 1
A factory operates a staff canteen and provides 10 EV chargers for company fleet cars. Both facilities operate with the same contract, encouraging load limits of 3 x 250A. During service hours, the kitchen consumes up to
150A on L1
100A on L2 and
100A on L3.
A signal is provided when the kitchen is not busy, and consumption falls below 10A.
- The EV charging infrastructure may consume 240A when the kitchen is not busy (=250A – 10A)
- As soon as the kitchen is not used, the control electronics provides a 12V DC signal and the full 3 x 240A may be used by the DLM system.
- When the kitchen is in use, the load of 140A ‖ 90A ‖ 90A needs to be thrown off to not exceed the 3 x 250A limit. In that case the DLM may only consume 100A ‖ 150A ‖ 150A.
Configuring the Master Charge Controller
Apply the following configuration:
| Location in Dashboard | Parameter | Value |
|---|---|---|
| Load Management > Dynamic Load Management | Dynamic Load Managemen - DLM Master/Slave | DLM Master (With internal DLM-Slave) |
| Load Management > Dynamic Load Management | EVSE Sub Distribution (L1/L27L3)[A] | 240 ‖ 240 ‖ 240 |
| Load Management > Dynamic Load Management | External Input 1 Config | Enable Opto 1 in |
| Load Management > Dynamic Load Management | External Input 1 Polarity | Active low |
| Load Management > Dynamic Load Management | External Input 1 Current Offset | -140 ‖ -90 ‖ -90 |
- At the bottom of the window, click , then click to apply the changes
Configuring the Slave Charge Controller
Apply the following configuration:
| Location in Dashboard | Parameter | Value |
|---|---|---|
| Load Management > Dynamic Load Management | Disconnected Limit [A] | 10 |
- At the bottom of the window, click , then click to apply the changes
Example scenario 2
A grid operator uses ripple control to throw-off loads. In this example, one (or multiple) 22kW wall-box must reduce load to 3 x 7A (5kW), when a control signal is low.
Configuring the Master Charge Controller
Apply the following configuration:
| Location in Dashboard | Set Parameter | to |
|---|---|---|
| Load Management > Dynamic Load Management | Dynamic Load Managemen - DLM Master/Slave | DLM Master (With internal DLM-Slave) |
| Load Management > Dynamic Load Management | EVSE Sub Distribution Limit (L1/L27L3)[A] | 32 ‖ 32 ‖ 32 |
| Load Management > Dynamic Load Management | External Input 1 Config | Enable Opto 1 in |
| Load Management > Dynamic Load Management | External Input 1 Polarity | Active low |
| Load Management > Dynamic Load Management | External Input 1 Current Offset | -25 ‖ -25 ‖ -25 |
| Load Management > Dynamic Load Management | Disconnected Limit [A] | 7 |
- At the bottom of the window, click , then click to apply the changes
Configuring the Slave Charge Controller
Apply the following configuration:
| Location in Dashboard | Parameter | Value |
|---|---|---|
| Load Management > Dynamic Load Management | Disconnected Limit [A] | 7 |
- At the bottom of the window, click , then click to apply the changes
Limitations of the Load throw-off function
- The load can not be reduced over time but only instantly
- With DLM, only current can be reduced, not power (reduction 32A 🡒 7A, but not 22kW 🡒 5kW)