Elements

Bus

pandapower OpenDSS

A bus is a connection point (node / busbar). Every other element must attach to at least one bus. Load-flow results show voltage magnitude and angle here — so set rated voltage (vn_kv) correctly before you run anything. The same result box also shows net bus P and Q; see On-diagram busbar results for the sign convention and how several generators or BESS units on one busbar are aggregated.

Documentation References: 📘 pandapower Bus 📗 OpenDSS Documentation

Parameters:

OPF note: Bus min_vm_pu / max_vm_pu are sent to the pandapower backend with each study. If limits are missing or inconsistent (e.g. max ≤ min) on a bus, Electrisim substitutes a wide 0.8–1.2 p.u. band for that bus only so AC OPF can converge on stressed networks.

Line

pandapower OpenDSS

Draw a Line as an edge between two buses (it is not a palette shape). Enter length and impedance, or keep the defaults for a first test. Use this for cables and overhead lines; use Impedance when you only have R and X between two buses.

UI defaults on drop: length_km 1, type cs (cable), endtemp_degree 250 °C, zero-sequence r0_ohm_per_km/x0_ohm_per_km 0.1 Ω/km, parallel 1, df 1.

Documentation References: 📘 pandapower Line 📗 OpenDSS Line

Parameters:

Load

pandapower OpenDSS

A load is demand at a bus (P and Q). Use constant power unless you have a reason for constant current or impedance. This is the usual way to model customers, motors-as-PQ, and plant auxiliaries.

Documentation References: 📘 pandapower Load 📗 OpenDSS Load

Parameters:

Harmonic Parameters (OpenDSS):

These parameters are used when running harmonic analysis with the OpenDSS engine. They define how the load injects harmonic currents and how the harmonic-frequency impedance of the load is represented. See also the Harmonic Analysis section for spectrum modes and workflow.

Motor

pandapower OpenDSS

An asynchronous motor. Use it when you need locked-rotor inrush for Motor Starting or a motor contribution in short-circuit. In OpenDSS it is mapped through a Load equivalent, not a native motor object.

Documentation References: 📘 pandapower Motor 📗 OpenDSS Motor

Parameters:

Asymmetric Load

pandapower OpenDSS

Asymmetric loads allow modeling of unbalanced three-phase loads where each phase can have different power consumption. This is particularly useful for distribution network analysis.

Documentation References: 📘 pandapower Asymmetric Load 📗 OpenDSS Load

Parameters:

Static Generator

pandapower OpenDSS

Static generators represent generators with static (PQ) behavior — for example photovoltaic systems or small generation units. For wind turbines with an editable P–v power curve, prefer the dedicated Wind Turbine element. In OpenDSS, a static generator is a Generator with Model=1 (constant kW and kvar), not a voltage-controlled Model=3 bus. Both static generators and wind turbines can be selected in Grid Code Compliance (P-Q).

Documentation References: 📘 pandapower Static Generator 📗 OpenDSS Generator

Parameters:

Wind Turbine

pandapower OpenDSS

A dedicated wind generation element based on the Static Generator model. Active power for load flow is always derived from a wind power curve P(v) and the configured wind speed — you do not set p_mw independently. Changing wind speed (in the element dialog or in Component Data) updates P [MW] immediately from the curve.

Palette: Sources (or Electrical abstract sources) → Wind Turbine. A worked example is File → New → offshore wind farm 1 GW (rev 6; 100 km export).

Documentation References: 📘 pandapower Static Generator 📗 OpenDSS Generator

Wind-specific parameters

In addition to the usual Static Generator fields, the Wind Turbine dialog provides:

Default dynamics plant kind is WIND for ANDES studies when renewable/IBR models are used.

Short circuit (IEC 60909)

On the Short Circuit tab a full-size converter (generator_type = current_source) is a current source. pandapower injects

Ik = k · Sn / (√3 · U)

When the Ik" field for the fault being solved is greater than 0, and rated power and reference voltage are greater than 0, Electrisim sets

k = Ik" · √3 · Uref / Sn

U_ref is Ik" reference voltage. Leave that box empty to use the voltage of the bus the turbine is connected to. The same k is correct on either side of the unit transformer, because the per-unit current does not change with the voltage ratio. R/X is used only for async and async_doubly_fed. A current_source ignores it.

If Ik" for that fault is 0, a Current Ratio k greater than 0 is used. If that is also 0, k stays 1.1, so older diagrams keep the previous contribution. A minimum short-circuit case contributes no converter current. Compare Ik" with the result ikss: the converter current does not decay between the initial and steady-state values. Peak current still uses the existing kappa path.

r2 and x2 are the negative-sequence impedance in per unit of S_n. They are applied only for two-phase and single-phase faults, as a shunt on the negative-sequence network. Three-phase faults are unchanged. Bus ikss, and the peak and thermal currents on that bus, include this shunt. Branch currents stay on pandapower’s assumption that negative-sequence impedance equals positive-sequence impedance, plus the fault-specific converter current. With x2 = 1 pu the machine branch is large beside a normal grid impedance, so the correction shows up mainly for a fault at a weak turbine bus. ANSI/IEEE C37 does not use these Ik" fields.

A new turbine, and a turbine whose Short Circuit Ik" fields were never filled, opens with these defaults. At 4.5 MVA and 30 kV the three-phase default is about k = 1.0 and the unbalanced defaults are about k = 0.5. Change Ik", reference voltage, or S_n on the Rating tab when the machine is different. Blank Ik" fields on an older diagram still fall back to k = 1.1.

Q capability (voltage-dependent, P and U)

The Wind Turbine Q capability tab defines reactive limits Q_min/Q_max as a function of both active power P and terminal voltage U (voltage-dependent Q limits). Enable Use Q capability curve so load flow applies the limits (pandapower enforce_q_lims and optional capacitive/inductive Q setpoint).

Built-in Q capability templates (stored in p.u. of S_n; confirm against OEM data):

• FRC WTG P–U (voltage-dependent) — PowerFactory type Fully Rated Converter WTG 2.5MW 50Hz: Q vs P and U. Default for new turbines (Q = 0 at P = 0; about ±0.44 p.u. Q at U = 1.0 and moderate P; Qmax shrinks at high voltage while Qmin stays near −0.44 p.u.).
• ±0.95 PF vs P (1D, U = 1.0 p.u.) — |Q| ≈ P·tan(arccos(0.95)) at each P; single voltage row. Same shape as the Static Generator 15 MW template, scaled to this turbine S_n.
• 15 MW offshore 1·Un chart (1D) — digitized manufacturer-style P–Q envelope at 1.0 p.u. voltage (asymmetric import/export).

Asymmetric Static Generator

pandapower OpenDSS

Asymmetric static generators allow modeling of unbalanced generation where each phase can produce different power levels.

Documentation References: 📘 pandapower Asymmetric Static Generator 📗 OpenDSS Generator

Parameters:

External Grid

pandapower OpenDSS

The external grid represents the connection to a higher voltage level or an infinite bus. It serves as the slack bus in power flow calculations and provides the voltage reference.

Short Circuit tab

Double-click the External Grid and open the Short Circuit tab. Positive-sequence strength is s_sc_max_mva / s_sc_min_mva with R/X ratios rx_max / rx_min. Zero-sequence ratios are required for IEC 60909 single-phase faults:

• Maximum case: Max R0/X0 Ratio (r0x0_max) and Max X0/X Ratio (x0x_max).
• Minimum case: Min R0/X0 Ratio (r0x0_min) and Min X0/X Ratio (x0x_min). Three-phase and two-phase minimum studies do not use these columns; single-phase minimum does.

If min zero-sequence ratios are omitted on an older diagram, Electrisim reuses the corresponding max ratios. Typical pandapower example values when no utility data is available: R0/X0 = 0.1, X0/X = 1.0. Related study: Short Circuit.

Documentation References: 📘 pandapower External Grid 📗 OpenDSS Vsource

Parameters:

Transformer

pandapower OpenDSS

Transformers connect different voltage levels in the network. They can be equipped with tap changers for voltage regulation.

Schematic Labels: Each transformer terminal can display a custom label on the canvas symbol (e.g. "HV", "LV"). These labels are purely cosmetic — they help identify which winding connects to which bus on the schematic, but do not affect simulation parameters or solver data. Edit them in the Schematic tab of the transformer dialog. Changes appear immediately on the canvas.

Documentation References: 📘 pandapower Transformer 📗 OpenDSS Transformer

Parameters:

Three Winding Transformer

pandapower OpenDSS

Three winding transformers have three separate windings, typically connecting three different voltage levels at one location.

Schematic Labels: Each of the three terminals can display a custom label on the canvas symbol (e.g. "HV", "MV", "LV"). These labels are purely cosmetic — they help identify which winding connects to which bus on the schematic, but do not affect simulation parameters or solver data. Edit them in the Schematic tab of the transformer dialog. Changes appear immediately on the canvas.

For the solver, Electrisim maps the three connected buses to HV / MV / LV by bus voltage (vn_kv): highest, middle, then lowest. If two buses share the same voltage, the original connection order is used as a tie-break so the mapping stays stable between runs.

Documentation References: 📘 pandapower Three Winding Transformer 📗 OpenDSS Transformer

Parameters:

Generator

pandapower OpenDSS

Generators represent synchronous generators with dynamic behavior. They are typically used for large power plants and have voltage control capabilities. For North American short-circuit studies, set ANSI machine type on the generator (used by ANSI/IEEE C37, beta).

Documentation References: 📘 pandapower Generator 📗 OpenDSS Generator

Parameters:

Harmonic Parameters (OpenDSS):

Slack concept by framework

The slack parameter in Electrisim applies to Pandapower load flow only. OpenDSS handles the slack bus differently:

For OpenDSS load flow, the slack role is handled by Vsource elements (External Grid), not by the Generator object.

Capacitor & Shunt Reactor

pandapower OpenDSS

Electrisim provides two separate shunt elements for reactive power compensation: a Capacitor (capacitor bank for leading reactive power) and a Shunt Reactor (inductive shunt for lagging reactive power). Both appear as separate components in the element palette and have dedicated dialog forms. Internally, both map to the pandapower shunt element, while in OpenDSS they map to the Capacitor and Reactor elements respectively.

Documentation References: 📘 pandapower Shunt 📗 OpenDSS Capacitor 📗 OpenDSS Reactor

Capacitor Parameters:

Shunt Reactor Parameters:

How shunt reactor parameters work together

The dialog is organised in three tabs. The relationship between “static” shunt data and “control” is:

1. Power tab — base P and Q. Here you set p_mw and q_mvar as the reference shunt power at 1.0 p.u. If you do not use a step characteristic table, the network model uses this pair together with step and max_step (equivalent shunt scaling with the step number).
2. Electrical tab — vn_kv. Shunt equipment rating; it must be consistent with the bus you connect to. It does not, by itself, turn control on or off.
3. Control tab — steps and the optional table.
   • step and max_step define the discrete positions of the shunt. max_step is the top step index you model (e.g. if steps are 0, 1, …, N, set max_step = N).
   • If Shunt characteristic table (step-dependent P/Q) is off, P and Q at the operating point follow the base values on the Power tab, combined with step.
   • If that option is on, you must fill the table so each step has its own p_mw and q_mvar at 1.0 p.u. Pandapower stores this as shunt_characteristic_table; OpenDSS applies the same rows to the Reactor. The dialog’s Fill steps 0…max step uses max_step to create empty rows you can complete.
4. Control tab — discrete shunt (voltage) control. This is a different option from the characteristic table (you can enable the table together with this controller, or use either alone). The table defines what P and Q are at each step; Discrete shunt control changes step so the shunt bus voltage moves toward vm_set_pu. When the table and this controller are both on, the controller only updates step; the injections at that step still follow the table. It cannot be combined with Line P → shunt step: turning this on shadows that block, and turning that one on shadows this block. For pandapower load flow, tick Shunt reactor tap changer under Include controller. For Grid Code Compliance (P-Q), tick Shunt reactor control in that study dialog. OpenDSS snapshot load flow runs the same loop when the option is enabled on the shunt.
5. Control tab — Line P → shunt step. A separate lookup: the solver reads P on a reference line and sets step from the band table (typical VSR behaviour). Only one step controller is active. While this option is on, discrete voltage control is shadowed, and while discrete voltage control is on, this block is shadowed. If an older element still has both flags stored, opening the dialog keeps voltage control and unticks the line-power lookup; that choice is written to the element when you apply. This mode is also gated by Shunt reactor tap changer on pandapower load flow, and by Shunt reactor control in Grid Code Compliance (P-Q); OpenDSS snapshot applies it after the solve.

Summary. Use the Power tab for a simple fixed or step-scaled shunt; add the characteristic table when each step has different P/Q at 1 p.u.; use discrete shunt control for a voltage target, or Line P → shunt step for flow-based VSR tap. Those two controllers are alternatives: the shunt dialog shadows the one that is not selected. If a table and a controller are both enabled, the table provides the per-step model and the controller selects the step. All of these are properties of the shunt on the single-line diagram; the pandapower load-flow dialog or Grid Code Compliance (P-Q) turns controller execution on or off for the run.

Impedance

pandapower OpenDSS

A branch between two buses defined only by R and X (not a physical line type). Use it for a coupling, a simplified equivalent, or a connection that is not a cable or overhead line.

Documentation References: 📘 pandapower Impedance 📗 OpenDSS Documentation

Parameters:

Ward

pandapower OpenDSS

A Ward equivalent stands in for a neighbouring network you do not want to draw in full: a constant-power plus constant-impedance injection at one bus. Prefer this over inventing dummy lines when you only have a reduced-network equivalent.

Documentation References: 📘 pandapower Ward 📗 OpenDSS Documentation

Parameters:

Extended Ward

pandapower OpenDSS

Like a Ward equivalent, plus an internal bus and impedance so the voltage response of the reduced network is more accurate. Use it when a plain Ward model is too crude at the boundary bus.

Documentation References: 📘 pandapower Extended Ward 📗 OpenDSS Documentation

Parameters:

Storage

pandapower OpenDSS

Storage elements represent battery energy storage systems (BESS) or other energy storage technologies that can both consume and generate power. Electrisim uses a unified Storage element that maps to both pandapower and OpenDSS. Dialog tabs: Power, Energy, Configuration, Optimization (OPF), Q capability (PCS P–Q envelope), OpenDSS Parameters, Inverter Control, and Economic.

Documentation References: 📘 pandapower Storage 📗 OpenDSS Storage 📗 OpenDSS Storage Properties

Parameters (Power & Energy)

Parameters (Configuration)

Parameters (Optimization – pandapower OPF)

Parameters (OpenDSS-specific)

These parameters apply when using OpenDSS for load flow, harmonics, or time-series simulations. They control the built-in inverter model, dispatch logic, and losses.

Q capability (PCS P–Q envelope)

The Q capability tab is the four-quadrant PCS envelope (not the wind-turbine ±0.95 PF triangle). Enable Use Q capability curve so load flow, OpenDSS kvarMax/kvarMaxAbs, OpenDER NP_Q_MAX_*, and BESS Dispatch Reversal apply Q_min/Q_max at the operating P.

Inverter Control

OpenDSS InvControl (and OpenDER on dispatch reversal) pick the Q setpoint inside the envelope. Watt priority chooses which axis is sacrificed when √(P²+Q²) would exceed S_n.

OpenDSS Implementation Notes

The following implementation details ensure consistent results between Pandapower and OpenDSS for storage elements:

• Power dispatch: Both kWRated (inverter capacity) and kW (requested dispatch power) are set explicitly. The state (DISCHARGING/CHARGING/IDLING) is derived from the sign of p_mw.
• Reactive power convention: Pandapower uses load convention (positive = absorbing). OpenDSS Storage uses generator convention (positive = supplying). The conversion is applied automatically.
• Reserve handling: When min_e_mwh ≥ max_e_mwh, the OpenDSS %reserve parameter is not set. This prevents blocking discharge in snapshot power flow when the reserve would otherwise lock 100% of stored energy.
• Connection and phases: The conn (wye/delta) and phases (1–3) parameters are passed to OpenDSS for correct modeling of single-phase or delta-connected storage.
• Inverter model: OpenDSS Storage includes a built-in inverter model with efficiency, idling losses, and dispatch modes. Pandapower uses a simpler PQ-bus model; time-domain SOC updates require custom scripting.
• P–Q envelope: When Use Q capability curve is on, Electrisim interpolates Q_min/Q_max at the operating P (PCS circle or custom JSON) and maps them to OpenDSS kvarMax / kvarMaxAbs. Optional voltage derate scales that band. Watt priority keeps P and clips Q at S_n (or the reverse if off).

BESS AC Block

pandapower OpenDSS

The BESS AC Block is a composite element available in the Storage palette (next to the Storage element). When you drag and drop it onto the canvas, it automatically creates and connects a complete Battery Energy Storage System (BESS) AC interconnection setup in a single step.

The block includes:

• BESS BUSBAR 1 — MV busbar rated at 33 kV (high-voltage side)
• Step-up Transformer — HV: 33 kV, LV: 690 V, connecting the MV and LV busbars
• BESS BUSBAR 2 — LV busbar rated at 0.69 kV (low-voltage side)
• Storage — Battery storage element (includes built-in inverter model) connected to the LV busbar

All four elements are pre-wired with correct connection points. Result placeholders for load flow and short-circuit analysis appear automatically for each busbar, the transformer, and the storage unit. You can connect the BESS AC block to your existing network by linking BESS BUSBAR 1 to your MV grid (e.g., 33 kV).

If you attach more than one Storage unit to the same LV busbar (BESS BUSBAR 2), load-flow P on that busbar is the net of those units — for example two units discharging at 1.75 MW each give −3.5 MW on the 0.69 kV bus, not −7 MW. The transformer LV/HV flows follow the same net. Details: On-diagram busbar results.

Documentation References: 📗 Storage 📗 OpenDSS Transformer 📗 Storage Properties

Note: The BESS AC Block is a composite palette template (MV bus, step-up transformer, LV bus, and Storage). It is not a separate backend element type — both pandapower and OpenDSS receive the four connected standard elements. Default drop values: MV bus 33 kV, LV bus 0.69 kV, transformer 33/0.69 kV, 1 MVA. You can modify all parameters to match your project.