Expertise in Power Systems Engineering

About us

Protrol Engineering AB was established in 2002 and is a private, independent consulting company, within the electric power and automation technology. The company currently has around 15 employees with a high level of education, Ph.D. and M.Sc., and long experience from work within Power Engineering. Protrol’s consultants offer engineering and expert services within the field of electric power systems. With a broad competence base, services are offered in several areas, including power system analysis, relay protection, generation, HVDC and electricity distribution.

Protrol’s experts have their background in power systems, electrical machines, power electronics or control systems. This includes expertise in analysis, modelling, simulations and control of power systems and its components. The engineers are advanced users of PSS/E, Power Factory, PSCAD, Matlab/Simulink and Python and have also long experience of testing power stations.


  • Kurs i spänningsstabilitet och spänningskollaps
    Upptäck en spännande kurs om Spänningsstabilitet och spänningskollaps, som presenteras i samarbete med Chalmers och Högskolan Väst. Mellan den 3-5 juni kommer våra erfarna medarbetare Evert Agneholm och Lena Max, tillsammans med Daniel Karlsson och Massimo Bongiorno från Chalmers, att guida dig genom en djupdykning i kraftsystemets stabilitet i ljuset av den pågående energiomställningen. Kursen … Continue reading Kurs i spänningsstabilitet och spänningskollaps
  • Vi välkomnar Jonas
    Vi välkomnar Jonas Olsson till vårt team! Jonas började hos oss den 1 december och kommer med lång erfarenhet från elkraftsbranschen; senast som projektledare och gruppchef på Ringhals, innan dess som konsult inom kraftsystemanalys. Välkommen till Protrol Engineering!
  • Välkommen Sara
    Vi välkomnar Sara Bengtsson som börjar hos oss den 3 oktober. Sara är en erfaren kraftsystemanalytiker som bland annat har jobbat med överensstämmelsesimuleringar, nätstudier och anläggningsprovning, vilket hon också kommer fortsätta göra hos oss. Välkommen till Protrol Engineering!
  • Elkraftdagen 2022
    Last Wednesday (30/3 – 2022), the student fair Elkraftdagen 2022 held place at Chalmers University, and Protrol Engineering participated as an exhibitor to show the future electric power engineers who we are and what we do. It was lots of fun talking to other players in the electric power industry and especially the curious students, … Continue reading Elkraftdagen 2022
  • Protrol Engineering participates at Elkraftdagen 2022
    We are happy to announce that Protrol Engineering will be participating as an exhibitor at this year’s electric power student fair, Elkraftdagen 2022!The fair, which is being held on the 30th of March, in the Volvo-foyer inside Chalmers Student Union building, is a fair/meeting place for students and companies who are interested in and working … Continue reading Protrol Engineering participates at Elkraftdagen 2022


Power System Analysis

We offer static and dynamic power system studies on several topics, such as:

  • Load flow and short-circuit calculations
  • Contingency analysis
  • PV and QV analysis
  • Frequency stability
  • Transient and voltage stability
  • Modelling of power system and components
  • Insulation coordination studies (lightning and switching studies)
  • Series compensation
  • Sub-synchronous resonance
  • HVDC and FACTS dynamic performance studies

Power Plant Studies

Protrol performs studies for all types of power plants such as combined heat and power, hydro, wind turbines, nuclear and PV.

  • Grid code compliance
  • Transient stability and low-voltage ride through
  • Protection studies
  • Power quality and harmonics. Filter design.
  • Motor start
  • Modelling of power plants and power plant components.

Validation of power plant performance

Validation of the power plant performance primarily comprises testing of governor and excitation system response. Protrol has elaborated a state-of-the-art plant test equipment based on in-house developed hardware and software with validated performance from both laboratory testbench setups and on-site tests. The test method supports both open-loop and closed-loop verification of controllers and equipment.

  • Frequency control.
  • Voltage control.
  • Island operation test (using hardware in the loop simulations)
  • Validation of simulation models.
  • Compliance testing in regards to RfG requirements
  • Pre-qualification tests for ancillary services (FCR-N/D, FFR, FRR, etc)


Michael Lindgren

Principal Engineer
Power Systems / HVDC
+46 706 08 66 83

Pehr Hjalmarsson

Principal Engineer
Power Systems / HVDC
+46 702 09 94 42

Thomas Nordlander

Principal Engineer
Power Systems / HVDC
+46 736 67 64 20

Torbjörn Karlsson

Managing director
+46 705 58 18 75

Stefan Enberg

Principal Engineer
Control systems
+46 70 620 65 00

Martin Mellbin

Principal Engineer
Control Systems
+46 70 980 53 80

Bo Almér

Principal Engineer
+46 70 265 50 58

Björn Fälldin

Principal Engineer
Control systems
+46 73 089 80 70

Evert Agneholm

Principal Engineer
Power System analysis
+46 732 49 89 20

Andreas Petersson

Principal Engineer
Power System analysis
+46 730 49 29 00

Lena Max

Principal Engineer
Power System analysis
+46 705 65 84 55

Magnus Loenheim

Principal Engineer
Power System analysis
+46 730 69 09 00

Gunnar Krebs

Principal Engineer
Power System analysis
+46 724 01 82 54

Gustav Holmquist

Principal Engineer
Power System analysis
+46 734 12 28 84

Nils Åkesson

Power System analysis
+46 738 21 90 02

Johan Olson

Power System analysis
+46 738 44 24 25

Sara Bengtsson

Principal Engineer
Power System analysis
+46 725 12 26 39

Jonas Olsson

Principal Engineer
Power System analysis
+46 708 84 45 25