hermess.devices.governor

Attributes

GOVERNOR_REGISTRY

Classes

Governor	Abstract base class for turbine-governor models (pluggable strategy).
TGOV1	TGOV1 turbine-governor model as presented in Power System Dynamics and
Droop	Pure speed-droop governor with the mechanical power 'pm' declared as a
GOVCONST	Constant mechanical power (no turbine/governor dynamics).

Module Contents

class hermess.devices.governor.Governor

Bases: abc.ABC

Abstract base class for turbine-governor models (pluggable strategy).

Every governor must expose ‘pm’ – the mechanical-power coupling variable consumed by the synchronous machine’s swing equation. ‘pm’ may be declared either as a differential state (when the turbine has lag dynamics, e.g. TGOV1) or as a device-private algeb (when mechanical power is an instantaneous / algebraic function of the inputs, e.g. a pure-droop or constant-power model). The host resolves ‘pm’ wherever it lives via Synchronous.var_sym – the swing equation is agnostic to the choice.

Symmetric to AVR: the governor does NOT own state arrays or DAE indices. It declares what states, private algebraics, parameters, noise values, etc. it needs, and the host Synchronous machine registers them on itself. It reads the machine’s absolute per-unit speed via host.omega (1.0 at synchronism, NOT the deviation) and its setpoint via host.Pref.

abstract states() → List[str]

Return ordered list of differential-state names.

Return type:

List[str]

algebs() → List[str]

Return ordered list of device-private algebraic variable names.

Default empty: most governors have turbine lag dynamics whose output ‘pm’ is a state. A governor whose mechanical power is an instantaneous function of its inputs returns [‘pm’] here instead of listing it in states(), and writes its defining residual 0 = -pm + <expr> into dae.g in fgcall().

Return type:

List[str]

algebs_units() → Dict[str, str]

Units for each private algebraic (mirrors units()).

Return type:

Dict[str, str]

algebs_x0() → Dict[str, float]

Initial guess for each private algebraic (Newton guess in finit).

Return type:

Dict[str, float]

abstract units() → List[str]

Return units for each state, same length as states().

Return type:

List[str]

abstract params() → Dict[str, float]

Return dict of parameter names -> default values.

Return type:

Dict[str, float]

abstract x0() → Dict[str, float]

Return default initial guess for each state.

Return type:

Dict[str, float]

abstract descriptions() → Dict[str, str]

Return descriptions for states and params.

Return type:

Dict[str, str]

abstract setpoints() → Dict[str, float]

Return setpoint names -> defaults (e.g., Pref).

Return type:

Dict[str, float]

abstract fgcall(host, dae: hermess.system.Dae) → None

Write the governor’s differential equations into dae.f and, if it declares private algebraics, their defining residuals into dae.g.

Parameters:

• host – The Synchronous machine instance. Access state/algebraic indices via host.psv, host.pm, etc., parameters via host.Rd, host.Tch, …, the absolute per-unit speed via host.omega and the setpoint via host.Pref.

• dae (hermess.system.Dae) – The DAE system object.

Return type:

None

class hermess.devices.governor.TGOV1

Bases: Governor

TGOV1 turbine-governor model as presented in Power System Dynamics and Stability by P.W. Sauer and M.A. Pai, 2006. (page 100)

States: psv (steam valve position), pm (mechanical power). ‘pm’ is the coupling output to the swing equation. This is the framework default.

The droop acts on the speed deviation omega - omega_net (omega_net = 1 p.u.); host.omega is the ABSOLUTE per-unit speed. Pref is the mechanical-power setpoint, so psv = pm = Pref at steady state.

states() → List[str]

Return ordered list of differential-state names.

Return type:

List[str]

units() → List[str]

Return units for each state, same length as states().

Return type:

List[str]

params() → Dict[str, float]

Return dict of parameter names -> default values.

Return type:

Dict[str, float]

x0() → Dict[str, float]

Return default initial guess for each state.

Return type:

Dict[str, float]

descriptions() → Dict[str, str]

Return descriptions for states and params.

Return type:

Dict[str, str]

setpoints() → Dict[str, float]

Return setpoint names -> defaults (e.g., Pref).

Return type:

Dict[str, float]

fgcall(host, dae: hermess.system.Dae) → None

Write the governor’s differential equations into dae.f and, if it declares private algebraics, their defining residuals into dae.g.

Parameters:

• host – The Synchronous machine instance. Access state/algebraic indices via host.psv, host.pm, etc., parameters via host.Rd, host.Tch, …, the absolute per-unit speed via host.omega and the setpoint via host.Pref.

• dae (hermess.system.Dae) – The DAE system object.

Return type:

None

class hermess.devices.governor.Droop

Bases: Governor

Pure speed-droop governor with the mechanical power ‘pm’ declared as a device-private ALGEBRAIC variable.

Primary frequency response without turbine lag dynamics: the mechanical power follows the speed deviation instantaneously (omega is the ABSOLUTE per-unit speed; the droop acts on omega - omega_net with omega_net = 1 p.u.),

0 = -pm + Pref - (omega - omega_net) / Rd # pm algebraic (no states)

so at steady state pm = Pref. This is the Tch, Tsv -> 0 (quasi-steady-state) limit of TGOV1: at Tsv -> 0 the valve gives psv = Pref - (omega-omega_net)/Rd and at Tch -> 0 the chest gives pm = psv. ‘pm’ rides the device-private-algebraic mechanism and the swing equation reads it through Synchronous.var_sym('pm'), as for a state-valued ‘pm’.

states() → List[str]

Return ordered list of differential-state names.

Return type:

List[str]

units() → List[str]

Return units for each state, same length as states().

Return type:

List[str]

algebs() → List[str]

Return ordered list of device-private algebraic variable names.

Default empty: most governors have turbine lag dynamics whose output ‘pm’ is a state. A governor whose mechanical power is an instantaneous function of its inputs returns [‘pm’] here instead of listing it in states(), and writes its defining residual 0 = -pm + <expr> into dae.g in fgcall().

Return type:

List[str]

algebs_units() → Dict[str, str]

Units for each private algebraic (mirrors units()).

Return type:

Dict[str, str]

algebs_x0() → Dict[str, float]

Initial guess for each private algebraic (Newton guess in finit).

Return type:

Dict[str, float]

params() → Dict[str, float]

Return dict of parameter names -> default values.

Return type:

Dict[str, float]

x0() → Dict[str, float]

Return default initial guess for each state.

Return type:

Dict[str, float]

descriptions() → Dict[str, str]

Return descriptions for states and params.

Return type:

Dict[str, str]

setpoints() → Dict[str, float]

Return setpoint names -> defaults (e.g., Pref).

Return type:

Dict[str, float]

fgcall(host, dae: hermess.system.Dae) → None

Write the governor’s differential equations into dae.f and, if it declares private algebraics, their defining residuals into dae.g.

Parameters:

• host – The Synchronous machine instance. Access state/algebraic indices via host.psv, host.pm, etc., parameters via host.Rd, host.Tch, …, the absolute per-unit speed via host.omega and the setpoint via host.Pref.

• dae (hermess.system.Dae) – The DAE system object.

Return type:

None

class hermess.devices.governor.GOVCONST

Bases: Governor

Constant mechanical power (no turbine/governor dynamics).

The mechanical power is pinned to the finit-solved setpoint,

0 = -pm + Pref ,

i.e. the zero-response limit of Droop (Rd → ∞). Used by models that deliberately exclude prime-mover dynamics, such as the 14-generator South East Australian benchmark (Gibbard & Vowles 2014), whose small- and large-signal models have no turbine/governor representation.

states() → List[str]

Return ordered list of differential-state names.

Return type:

List[str]

units() → List[str]

Return units for each state, same length as states().

Return type:

List[str]

algebs() → List[str]

Return ordered list of device-private algebraic variable names.

Default empty: most governors have turbine lag dynamics whose output ‘pm’ is a state. A governor whose mechanical power is an instantaneous function of its inputs returns [‘pm’] here instead of listing it in states(), and writes its defining residual 0 = -pm + <expr> into dae.g in fgcall().

Return type:

List[str]

algebs_units() → Dict[str, str]

Units for each private algebraic (mirrors units()).

Return type:

Dict[str, str]

algebs_x0() → Dict[str, float]

Initial guess for each private algebraic (Newton guess in finit).

Return type:

Dict[str, float]

params() → Dict[str, float]

Return dict of parameter names -> default values.

Return type:

Dict[str, float]

x0() → Dict[str, float]

Return default initial guess for each state.

Return type:

Dict[str, float]

descriptions() → Dict[str, str]

Return descriptions for states and params.

Return type:

Dict[str, str]

setpoints() → Dict[str, float]

Return setpoint names -> defaults (e.g., Pref).

Return type:

Dict[str, float]

fgcall(host, dae: hermess.system.Dae) → None

Write the governor’s differential equations into dae.f and, if it declares private algebraics, their defining residuals into dae.g.

Parameters:

• host – The Synchronous machine instance. Access state/algebraic indices via host.psv, host.pm, etc., parameters via host.Rd, host.Tch, …, the absolute per-unit speed via host.omega and the setpoint via host.Pref.

• dae (hermess.system.Dae) – The DAE system object.

Return type:

None

hermess.devices.governor.GOVERNOR_REGISTRY: Dict[str, type]